[10.23.12: this worked, but i need more practice. i only had flat toothpicks, so maybe a round, pointed toothpick would make a difference. out of the three I painted, one came out really cute.] Easily paint a heart with a toothpick.
27 Nail Hacks For The Perfect DIY Manicure - A must have for everyone who enjoys simple but different nail art :) (I haven't tried all of these, but most of them are worth a shot. Just please ignore the one about licking your nail polish)