Some of my friends who are not polish fanatics asked me to make some posts on nail polish basics. So I'm starting with base coats!
I will admit that when I started doing my nails a lot, I didn't use base coat. After doing some reading, I decided to get a bunch of base coats so that I could see what would work best.
So why do you need a base coat? Well, base coats do several things. They protect your nails from staining from dark colored polishes and getting yellow. They help adhere polish to the nail for a longer lasting manicure or pedicure, while giving the nail a cleaner, more even surface to work with when you apply the polish. A lot of base coats today come with vitamins/proteins added to them to help strengthen your nails and to prevent them from getting too brittle and dry (and then cracking or peeling). So wearing a base coat is a good thing and definitely something you should do if you plan on painting your nails a lot or a little! You want to keep your nails happy and healthy while you're wearing polish.
So how do you choose a base coat? This is a little trickier. Some people swear by drugstore brands such as Revlon or Sally Hansen, while others love the more "designer" brands: OPI, Orly, CND, Seche, etc. My advice is to buy a few and test them out yourself to find something you like. What works for others may not work for you. You may want a ridge-filling base coat to make your nails more even, or a base coat that has added ingredients to strengthen your nails. Or maybe an extremely "sticky" base coat to ensure your manicure lasts a long time if you don't intend on changing your polish for awhile.
Another thing to consider: base coat primer. Your nails need to be clean and oil free before applying your polish-- so make sure to use nail polish remover to clean your nails a couple of time prior to applying base coat, at least. Some companies also sell "base coat prep" or "base coat primer" which seems to be mainly a solution of isopropanol to clean and quickly evaporate off the nail before applying base coat.
Next question: do you need to use each brand's base coat with that brand's polish? My answer, with my own limited knowledge and perusal of other nail polish blogs is NO. In fact, a lot of bloggers seem to find a brand of base coat they like/works for them and use that with everything. There are some brands where I tend to prefer that brand's base coat with the polish (RBL, Zoya, and now Essie) but most of the time I tend to use Seshe Base with my polishes.
So where do you buy base coats? Well, if you can find an Ulta or some other beauty store (or drug store) near you, that's probably your best bet. If they carry a bunch of different brands you can pick out a few to try. If not, your next best bet is to shop around online-- you also might be able to find some for cheaper than retail price at places like Nail Supplies (formerly TransDesign), though beware, because with shipping it may not end up being an cheaper.
My base coat collection:
From left to right: Revlon Multi Care Base + Top Coat (not recommended), Orly Bonder, OPI Natural Base Coat, Seshe Base Coat, Essie First Base, Zoya Anchor, Rescue Beauty Lounge Base Coat Prep and Base Coat.
An article here has some good suggestions and tips for nail polish application as well. I will be doing a post on top coats later on! I hope this was helpful to my non-fanatic friends, at least in terms of being a primer for why you should use base coats and some of the things that are out there.