I recommend 9dp size cause it's better to animate bigger things with that but u might have problem how small it is cause some people have eye problems so for them it's better to use 10 or 15 size but my recommendation is 9dp

I probably recommend 9dp size it way easier with that cause it's smaller size and I mostly recommend to use smaller size

Well my pixel size is 9dp but sometimes I use it 30 or 20.(2 answer)
Um are u doing drawing on pc or phone because I use phone and in phone I use my fingers but in pc u have to use a mouse....only after that i can answer ur question

Um.. question
How do you use the pen/ brush smoothly without seeing any pixels??
I kinda have a problem with that and
2. What's the recommended pixel size for the brush/pen