All you need are scissors and name tags!
That is, presuming your design is small enough.
This idea can easily be adapted to all kinds of sturdy objects, particularly outdoor stuff and items that you aren't worried about the labels damaging whatever surface they are applied to.
I wanted to spray paint our rain barrels, but I also wanted to leave a bit of the blue showing, as the plastic is such that you can kind of see through it to tell how full the barrels are.
1. Draw and then cut out your petals. If the edge of the design includes the edge of the sticker, it will be much easier to separate the sticker from the backing.
2. Apply your name labels. Don't stick the whole thing down firmly--leave a bit so you can easily pull the label off. Make sure to apply the stickers so all of the not-stuck-bits are in the same place on the petals, as there will be a blurred edge in those places and if ALL the petals have the same blurred edge in the same place, it will look like it was done on-purpose.
3. Spray paint everything. Let it dry completely.
4. Peel off the name tag labels/stickers.
5. You can carefully scrape off the residue or let it wear away eventually.
6. Enjoy your pretty flowers!