I wanted to decorate my son's room a little better now that we've settled in our new house. I figured bright stripes in the color of his favorite ninja turtle would do the trick.
1) large level - the nice kind used by carpenters
2) colored pencil in a shade of your stripes
3) tape. not optional, no matter how pro a painter you are
4) painting supplies, paint, rollers, trays, etc. I'll assume you've painted before!
Step 1: Tape & Prime
Make sure your walls are ready for painting.
You have to be especially careful with exact lines when you place the tape. Every little mistake will be visible in the resulting stripes.