I've been using StickerMule recently for all of my sticker-ing needs and they make things super easy to use. I love using their studio and it's great because whatever I envision always comes out extremely accurate to the mock up. The pricing is also great (especially if you catch your order during a sale) and the timing is extremely efficient. I ordered 200 stickers and needed it within the week and was able to pay for regular shipping and received the order 4 days later (3 days earlier than predicted)!
Would strongly recommend using StickerMule (2x2 is a great small size for cute stickers).

Amazing Accuracy!