I know for a fact that I can't be the only girl in the world who does a not so good job at painting my nails. The struggle is real. And, by the time you get them all painted, the nailpolish is all over your hand and fingers and probably your bedspread too. Then, you have to deal with not doing anything with your hands for like 10 or more minutes, which really sucks.
Most people prefer to go salons and get their nails and toenails mani-pedi. That's not always an option, of course, especially when you are rushing out the door to get to school, or a date, or work, etc. on time.
I highly recommend buying Sally Hansens, stick on designs. Or, at least making sure that you outline your nails with tape before you paint them, to keep the paint from getting everywhere and ruining your whole outfit.