Birthday Gift- If you are a teen, or tween, a good idea would be to choose a color, and buy everything in that color. If my friends favorite color was blue, I would buy blue nail polish, blue earrings, blue necklace, blue sunglasses, etc. But you don’t want to choose a color they don’t like. You can also get them a little wallet and put a gift card inside. But make sure your friend sees the gift card before using it so they don’t accidentally throw it away.
Party Favors- The same as above, but if you don’t want to go to that much trouble, just choose a variety of nail polishes for the guests to choose which color they want. But if you think there will be an argument, get all of a neutral color, like silver. If you don’t want nail polishes, you could buy or make pretty beaded bracelets, or really any type of bracelet.
Hope this helped!