#1 Do it yourself Dotting tool
Take a paper pin and stick it in pencil eraser. It will make uniform dots in your nail arts.
#2 Use band aid for the perfect French tips
#3 Erase smudges using a q-tip dipped in nailpolish remover
#4 Use an old eyeliner brush to create stripes
#5 Use Scotch tape for crisp lines
Hope you find it useful