Important Tips!
Now, I'm by no means a nail art expert but here are some tips I've come up with that may help you out!

1. Nail polish can be difficult to work with when doing nail art; It gets expensive, the formula can be too thick, and it can ruin your brushes. If you don't have a variety of polishes at your disposal, acrylic craft paint works just as well. I wouldn't recommend it for your base coats but for small details, it works great. On all of the nails picture above, I used black and white paint for the eyes and mouths. If you do put it directly onto your nail, make sure you apply a coat of clear polish onto your nail first; I wouldn't recommend painting it directly onto your nails. I'm not sure of the effects of it but it just doesn't seem like a good idea.

2. A good brush is the key to clean, successful nail art. You want a small, tapered brush that ends in a fine point for little details like faces and eyes. Stray brush hairs can also result in messiness so trim them off. You can also use toothpicks to dab on details. Applying details in little dots as opposed to long strokes can be the key to clean details. Nail art pens are great for applying strokes of color but not a good idea when it comes to small details. See below: