Tips to prevent bleeding?

I know this question most likely gets asked a lot, but I can't figure it out.

I seem to do everything correctly. I iron the freezer paper, sticky side down, really nice and make sure no edges are up. I spray my 50/50 mix of bleach and water and dab around with paper towel, and yet it still bleeds and makes my design look blurry and rounded.

Could I be spraying too much mix? Or is there something else I should try like a hard plastic stencil?