Likely there will be quite a few issues with your map that I'd want to discuss, and I've essentially found myself repeating the same things over and over again. So I thought I'd put it all here. This is, of course, mostly just one style of mapping (guess I'll call it percussion style or something), but it would be better to get to grips with this style, which is an easier style to learn than most, before going away from this and experimenting.

General Information

1. Check AIMod. The number of times I come in and there are still problems here is crazy. It's often just simple checks like unsnapped notes and kiai toggles that are overlooked.
   
2. The maximum bitrate for audio files is 192kbps, minimum 128kbps. Check this by looking at the properties of the audio file in the song folder. AIMod will also try to pick up this problem.
   
3. Custom hitsounds must have a maximum delay of 5ms. Preferably, they should have no delay at all.
   
4. Background need to optimally be 1920*1080 for 16:9 or 1920*1200 for 16:10 (as these are the maximum rankable dimensions.)
   
5. Don't leave unused files in folders, as they take up unwanted space since the maximum permissible folder size is 30MB.
   
6. OD and HP: Generally speaking, between 6 and 9 for both is fine, but don't do something silly like odhp 9 for an Easy or odhp6 for an Extra. Usually having these values up to 1.0 apart is normal, as long as the idea of progression is still present within the map.

Slider Velocity (SV) Changes
There is both a Standard Guide and Simplified Guide available for use.

The two key things are:

1. Make sure they're averaged so the overall section is still sightreadable (best way of doing this is maintaining the 1x average mentioned in the guides)
2. Use them appropriately. There shouldn't be any random SVs in the map.

Charting
First thing's first. I'm going to say mapping notes to vocals or to more or less any form of lead for an extended period of time is strongly discouraged and should be avoided. There's nothing technically wrong with it, but with following sounds for mania (what you should be doing, might I add), it can get a little cluttered, particularly for 4K and following vocals is the first thing to be dropped.

Going off of that, unlike standard, there are no filler notes in mania. That means that, if there aren't any sounds about, there shouldn't be anything there. Vocals aren't really considered as sounds for this as they're not as clear-cut as something like percussion. If there are notes where there aren't sounds, then those are ghost notes.

Avoid "anti-ghosting" as well, which is not mapping something that should be. For example, something like a snare sound shouldn't be missed. It's more often than not a problem for easier difficulties, as you can't really map many things that appear on 1/4s at high BPMs. The easy solution is to "cover the sound" with a long note (LN). A good place where people use this is in drum fills.

The thing to come after this is consistency, which is essentially mapping the same sound with exactly the same number of notes, well, consistently. A common thing would be to map bass kicks for the harder difficulties as doubles, and this would be the same throughout the rest of the map. Occasionally this can be broken, but there needs to be a very good reason as to why.

"Variety is the spice of life", as they say. Remains true for this too, you know. It's not wrong to be repetitive, but being varied (while being consistent) can make a map interesting.

Another important factor is playability. Essentially, it's trying to ensure that the patterns you map are somewhat comfortable. Of course, you can go against this, but you're going to need a reason to the tons of modders who will point it out. It's important to playtest your map often and think about the players it will be aimed for. (The most common way most people do this is through spreading the notes out across all of the columns evenly.)

Lastly, progression. Easier difficulties should essentially be a more basic version of harder difficulties, rather than a different entity altogether. Simply, there shouldn't be anything in an Easy or Normal that would be absent in a Hard or an Insane, for example. The other thing is, there can't really be too much of a difference between difficulties, as the jump would be unreasonable to players trying to progress onto the harder difficulties.

If anything, practice will improve your mapping skills, as it does anyone. But knowing about these will certainly help, as it has for me.

Of course, if there's anything here that you don't understand, feel free to PM me somewhere... or request here.

4K and 6K only please, since those are my main keymodes. I tend not to map what I can't play, so don't go asking for 6* diffs. Past GDs I've done can be found on my userpage.

I will get to these, I swear...
(Note: Just because your map is here doesn't mean I'll mod it. I'll normally quickly look at maps initially then take a more examined look once they reach the top of the list. Opinions and drive change a lot you know...

Also just because it's not here doesn't mean it won't get modded either. Occasionally I get people who ask to snipe maps from my queue.)

1. Parachor: Ekcle - The Impulsive State (NM) "SV"
2. Minseo2000: Sakuzyo - AXION (NM) "LN"
3. Calcyon: Nekomata Master feat. Sana - Indigo Bird (NM)
4. - Ly0572 -: FREDERIC - Kanashii Ureshii (NM) "5k"
5. -I K I- : Akitsuki Fuuka (CV:Lynn) - Climber's High! (The Fallen Moon Version) (NM)
6. dudehacker: Moso Calibration - Seishun Prologue (NM) "7k"
7. Virtue-: Halozy - Songs Compilation (NM)
8. atian540: senya - Yureru Koi wa Nami no Gotoku (NM)
9. Nevertary: Nanahira - Bakubaire! Match Uri no Haken Shoujo (NM)
10. Faing Fain: kamome sano - Freaky Freak(Extended edit)
11. Salty Mermaid: F-777 - Airborne Robots

On hold:

1. [ amb1d3x ]: Touyama Nao & Hanazawa Kana - Taisetsu no Tsukurikata (Asterisk remix) (NM)
2. Umo-: Taishi (NM) (metadata?)

March 2017 (when I opened the queue)

1. JesusMD24: saradisk / 220 - Kumano (NM) {30/3/17}
2. - Ly0572 - : saradisk - 222 - wewewe (NM) {30/3/17}
3. Litharrale: TiA - The glory days (M4M) {30/3/17}
4. JooF12: LiSA - Catch the Moment (NM) {31/3/17} (hitsounding only)
5. Shiro-neechan: Tatsuya Yano - Let's Try It! (NM) {31/3/17}

April 2017

1. 7kitte: Hyadain - Hyadain no Joujou Yuujou ~TV size~ (NM) {2/4/17}
2. Barusamikosu~: fhana - Aozora no Rhapsody (M4M) {2/4/17}
3. Nevertary: Himeringo - Yotsuya-san ni yoroshiku (NM) {2/4/17}
4. CrumpetFiddler: KEYTALK - Starring Star (M4M) {2/4/17}
5. YaHao: Kobaryo - Dotabata Animation [feat. t+pazolite] (NM) {2/4/17}
6. Deextra46: Sound Horizon - Raijin no Hidariude (NM) {2/4/17}
7. FadillSan: Tatsuya Kato - DETERMINATION (NM) {3/4/17}
8. Rivals_7: Rhodanthe* - Happy * Pretty * Clover (NM) {3/4/17}
9. Roger06150: Veritas Unae - ~DISK 1~ (NM) {3/4/17}
10. Eldergleam: SHK - Last Rebirth (NM) {4/4/17}
11. wamster2: Fourfolium - Now Loading!!!! (NM) {5/4/17}
12. Shiro-neechan: Nishimori Yusa(CV.Uchida Maaya) - Rakuen made (M4M) {5/4/17}
13. FelixSpade: M2U - Wicked Fate (NM) {5/4/17} (primarily hitsounding)
14. genkicho: ICE - citanLu (NM) {6/4/17}
15. Eldergleam: Kenshi Yonezu - Peace Sign (NM) {6/4/17}
16. Amiichii: Tamura Yukari - W:Wonder tale (NM) {6/4/17}
17. Rammler: TOMOSUKE x Jazzin'park - LANA - Kiroku no Kakera (sasakure.UK Framework Remix) (M4M) {15/4/17}
18. OMGitsRaMayu: Hanasaka Yui(CV: M.A.O) - Harumachi Clover (NM) {16/4/17}
19. Alberiansyah: Ice - Entrance (NM) {16/4/17}
20. Virtue-: lapix - NEO GRAVITY (extended) (NM) {18/4/17}
21. FadillSan: Aquors - Happy Party Train (NM) {20/4/17}

May 2017
None from the queue, because exams...

June 2017

1. Ilham: enzo + O2i3 - Mentanpindoradora (NM) {6/6/17}
2. JooF12: EYKHA (CV : Sawashiro Miyuki) LOU (CV : Uchida Maaya) MERYL (CV : Terui Haruka) - Delta Decision (NM) {7/6/17}
3. Unpredictable: Graeme Cornies & Dawna Toews - I Wanna Be Famous (NM) {7/6/17}
4. AchsanLovers: Qrispy Joybox feat.Chata - Yuuki no Pendant (NM) {8/6/17}
5. Satania Daimaou: Haruna Luna-Ripple Effect (NM) {9/6/17}
6. [B A D]: Thaehan - Final Boss (NM) {9/6/17}
7. Ayachi Meme: Brad Breeck - Fury Heart (NM) {9/6/17}
8. jason1024: Earth Star Dream - Kimiiro ni Somaru (NM) {10/6/17}
9. ChochoaLatte-: ELISA - Real Force (NM) {12/6/17}
10. Mykaterasu: Camellia - Exit This Earth's Atomosphere (NM, marathon) {12/6/17}
11. FadillSan: Kousaka Honoka (CV. Nitta Emi) - Mou Hitori ja nai yo (NM) {13/6/17}
12. _Stronger_: Daniel Brown - Rabi-Ribi Piano (Timing) {18/6/17}
13. Syadow-: nano - rock on. (NM) {27/6/17}
14. Virtue-: GARNiDELiA - SPEED STAR (NM) {28/6/17}

July 2017

1. - Ly0572 -: KOTOKO - Koi Kou Enishi (NM) {3-4/7/17}
2. Mentholzzz: Triodust - Ju Tou San Chi Tian Qi Qing (NM) {4/7/17}
3. Incendent: Helblinde - C204 (NM) {4/7/17}
4. OwenF04: Nao Tokisawa - Brynhildr in the Darkness (Ver. Ejected) (NM) {17/7/17}
5. Incendent: Kushi - Sakura no Zenya (Speed up Ver.) (M4M probably lol) {18/7/17}
6. CrumpetFiddler: KEYTALK - Starring Star (NM) {25/7/17}
7. Mystical: Sawai Miku - Colorful -TV Size- (NM) {26/7/17}
8. DarkFire: Kana-Boon - Ki oon (NM) {29/7/17}
9. Shintoryu: Trustick - Flying Fafnir (NM) {29/7/17}
10. newbandpro: F-777 - Dance Of The Violins (NM) {29/7/17}

August 2017

1. 3stan: MAX - Requiem (M4M) {10/8/17}
2. Acnos: DONUT QUINTET - PLATINUM JET (NM) {10/8/17}
3. Emperor of Time: saradisk - 164 - Koushou remix (NM) {10/8/17}
4. Chibitania: cosMo@Bousou-P - Sadistic.Music Factory (NM) {11/8/17}
5. deadbill: Yonaki Yasha (Ashay) - Blood (NM) {12/8/17}
6. Syadow- : Tamura yukari - endless story (NM) {13/8/17}
7. [ Blaze ]: Draw the Emotional & Foreground Eclipse - Stay by my side (NM) {29/8/17}
8. Ridho 2307: Team Grimoire - MOTHER FUCXXXXXer (NM) {30/8/17}

September 2017

1. [AngelMegum1n]: Treyarch Sound - 115 (NM) {2/9/17}
2. OscarRickyH02: Camellia - Algorithm (NM) {2/9/17}
3. Mentholzzz: fhana - tiny lamp (M4M) {3/9/17}
4. AchsanLovers: Silent Siren - Hachigatsu no Yoru (NM) {3/9/17}

(NB: Difficulties here refers to the ones you want me to pay particular attention to, not however many there are in the mapset)
Also a silly question for you: If you had 24 hours to live, what would you do?

Type of request:
Artist/Title:
Link to your map:
Length:
Difficulties: (that you want me to mod)
Extra notes:
Key count:
If I had 24 hours to live, I would...