This would be so much more useful if everyone had the ability to help the last user who posted and gave advice.
Then they would put their weakness up next for the next person or something. (Too bad it would take too much effort if you don't say "just keep playing")
I'll try it, actually.
Takamaru_17, I too have that slow stream problem, but I usually fix it in the middle of the playthrough. You just have to be decisive. You could keep trying to use one finger or use both and get used to the timing. Don't switch between the two or think about the other mid-song and you should be fine.
As for jumps...That's kind of a broad term and because of that, you'd just have to play a lot of maps to get used to a good portion of them. For more specific jumps, there are beatmaps that have mostly jumps that can get you used to the simpler stuff. I wish I could tell you how to find them, though. I kind of want to get better at jumps myself.
My biggest weakness in osu! is probably reading. A lot of songs I want to beat have odd rhythms and circle, slider, and stream positions and directions. One of the most disappointing losses for me is when I lose after messing up easy jumps just because I'm not good enough at reading it.