Just like applying foundation to dirty or oily skin is a big no no, causing problems later on to your over all makeup application, not properly cleaning the surface of your nails before polishing is like the same thing.
Before applying your base coat (the foundation of your paint job) make sure your nail surface is free of any oils by using alcohol or a nail prep product like CND Scrub Fresh on a lint free nail wipe or pad. I’ve been using the Hands Down Lint Free Nail Wipe Pads with plastic backing for years, I’m talking 10+ because I’m THAT manicurist who always has her nails polished and the plastic backing really helps to protect my own nails from all of the polish removing I have to do on set. But the 2×2 squares from Hands Down is the better choice for at home use. Be sure to rub the surface of the nail all over and even under the edge of the nail. And to take it a step further, take a angled eye liner brush, dab in the your prep product and swipe around the cuticle area and sides of the nails. Your goal when nail prepping is dehydration, but I like visuals, so you want a “ashy” look to the nail surface. Follow up with your base coat, two coats of color, keeping in mind that thinner coats are better and then top it off with a high shine top coat.
Again, foundation is key to most of our beauty ritual outcomes, give nail prep a good detailing and this mos def will help with your nail polish lasting longer.