different colors of paint (you don't need very much)
a pair of plain jeans (with no designs on them already)
STEP ONE: lay your jeans outside or in a place where you don't mind getting paint all over the place.
STEP TWO: dip your paintbrush in some paint and flick towards your jeans, making a splatter of paint on your jeans. Do this all over your jeans with different colors.
STEP THREE: Wait for the front side of you jeans to dry (usually takes 24 hours) then flip them over and do the backside the same way.
STEP FOUR: Wear them to school, and when someone comes up to you and says "Where did you get those they'r cool" you reply in a perfect tone"I made them!" then leave your questioner gazing at you with great wonder!