Nail Fresh is the best product for cleaning up any polish mistakes because it evaporates so quickly that it never makes the polish go sticky.
It will remove polish from the skin or around the cuticle line to make it sharp ... anything like that. Using an old brush dipped in Nail Fresh is so much easier and less messy than those pen things that get gunked up immediately if you use them on say, red polish ... it is always necessary to be changing tips!!
However, you must have one bottle dedicated to doing this job which is separate from any bottle you use for preparation.