>>5867919this guy gets it but should be nice and explain it.
ex. you are drawing an arm coming towards the frame. It doesnt feel right. Make a new layer and draw a quick box around each segment of the arm in perspective. it should be way easier. cut the boxes diagonally from corner to corner with a line. If the lines are parallel across your shrinking/growing segments you're good. If they arent parallel you fucked up.
Think of it like a 10-20 second checkup to see if your shit looks right.