When it comes to reading notes, there is a lot to say.
Firstly, note colour. There are skins that keep the note colours all the same, or change depending on if it is an LN, or use multiple colours to differentiate multiple lanes. Personally, I'm a half & half guy. With that note coloring, I can sometimes focus on both halves of the lanes like 2 two lanes instead of 1 four lane, if you get what I mean. I can only speak as a 4-key player though.
As far as reading notes goes, most people will say read somewhere near the middle, read where the notes are not located (the space between them) and learn the patterns.
Although it does very much come down to muscle memory, there's still a few tricks that can make note reading easier. Reading spaces in between notes is a huge one.
As well, I read notes as directions the notes are coming from for streams especially, if I should tap rightward (left to right) or vice versa because thats how the notes look to me, when to change direction, etc.
Sometimes, I may read clusters of notes as shapes and determine how to hit them, like a 21-2 jack would be a "triangle" for me.
If it's multiples notes at once (chords) you suck at hitting, I think I got over them by pretend playing, pretending I was playing a pattern without actually being in any game and it somehow with proper technique lead to proper reading. That can apply to more patterns. I think it was the result of me being bored of waiting for computers to load and open at school that I started fidgeting like that.
I don't know if I'm overcomplicating the simple act of reading notes. It's just me writing how I feel I got over reading certain patterns. The most important trick though I think is to simply look at the pattern. Turn on autoplay or watch a video and just look at that pattern because it's easier to read patterns when you're not playing, then play after. These are all just general suggestions and observations I made as I improved.
(Any edits made are for clarifying my sentence or improving its structure)