It's so simple and really you can't go wrong with watercolor. It will look good cut into a design, you don't need any art skills, and it's simple!
You basically just need 3 things and you can find them all on Amazon.
Paper, Watercolor set, and watercolor brush.
If you are only going to make one and be done I wouldn't go all out. Just get one cheapo little paintbrush from Michaels/Hobby Lobby etc, and a cheap paint set and watercolor pad of paper.
If you want to make a few though (it's addicting and relaxing so you probably will) I would recommend getting the following:
Watercolor Pan Set
My main one I use is Prima Marketing Classics
Prima Marketing has a LOT of different watercolor sets. You may find you like the colors in another set more that's up to you. I just wanted basics since I had nothing to start with.
Next I got this set of paint brushes for a variety of sizes
Lastly, you need watercolor paper. It's important to make sure it's for watercolor otherwise it won't hold up.
This is the one I use
That is all!! Get these 3 items or something similar and you can easily make yourself a watercolor vinyl pattern.
I'll do another post later this week or next weekend on tips for making it.
If you don't follow me from Instagram and don't know this you can have your own custom designs printed on adhesive and heat transfer vinyl from Sparkleberry Ink.