Hmm interesting. What type of notes do you take usually? MU specific or general notes on the character?
I usually start with spacing. So where do my buttons reach? Where does my opponents buttons reach? If someone has a projectile, what are the responses to either on the field? Anything quick or tricky I should be on the lookout for (think v-bison moves)? I'll probably take this time to take note of frames. What's quick, plus, negative. Then once I have those basics I look at my opponents general game plan and how it intersects mine. Basically what am I looking for/to do, what are they looking for/to do. One interesting example I've noticed is Bison gains v-gauge by absorbing projectiles. So just by being patient and quick, bison can pretty much take away the fireball game. Mika on the other hand stays close and reacts with ex peach, or makes a read with st.HK. In F.A.N.G. Versus Zangief, F.A.N.G. Can coward crouch Gief st.HP on reaction for a full combo. Then after that It's all basic tools and gameplay in different situations. Off anti airs, wakeup, corner, meter count, Etc. Which I guess would be more in depth stuff.