The original article by Cosmo Mag can be found here... but there are a few tweaks that I, a professional nail tech, would like to point out/make:
**First -- the title. You do not "paint" your nails, you "polish" them. Yes, technically, paint in a can and polish in a bottle are both a type of lacquer... but they are different. You wouldn't use your polish in a bottle to paint your house or vice versa, would you? No.
1. Yes, three strokes *is* best, but don't worry if you don't get it in three... heck, sometimes it takes me five. As long as the polish is still liquid-y enough to work with without it streaking, it's fine. Also, you'll want two-three coats of color (more on that in #9).
2. There are a few exceptions... VERY few! CND's Vinylux is one of them; no base coat needed (but it won't hurt to use one, either). Darker colors ESPECIALLY need a base coat, or you're going to end up with stained nail plates.
3. Great advice. I also love these pointed Q-tips (other brands make them, as well).
4. Yes. White, especially bright white, is one of the most PITA colors you'll ever deal with... but if you can find the right shade and apply it well, hats off to you! :)
5. The only quick-dry polish you should be using is Top Coat (it'll help dry your polish faster) or when stamping; they're perfect for that.
6. YES YES YES!!! Cuticle oil also comes in drop form, if you are worried about brush strokes on your fresh manicure. However, you cannot apply it too much. I recommend twice a day; more if your hands are in water and you're not wearing gloves (WEAR GLOVES! -- more on that in #16).
7. No. Just don't do this. Trust me. Polish dries by evaporation; dunking them in cold water does NOTHING to speed up that process. I *do* suggest drying drops, though (also comes in a spray form); my go-to is Drip Dry by OPI).
8. Yes, do this... this is good advice. Try for a full-coverage one-coater white, if you can find one.
9. Yup, this is great advice, too. Thick layers take way to long to dry.
10. It does help polish to last longer by keeping it in a cool, dark (away from sunlight, lamps, heaters, etc) place... *but* refrigerating them isn't good for them. IF you want to keep them in the fridge, fine, but make sure you take them out and let them warm to room temp before using them. Honestly, a better idea is to find a shelf or cabinet somewhere (bathroom, closet, etc).
11. Yes. Make sure you're not using more than a couple drops at a time, and do not ever substitute polish REMOVER; that will ruin your polish in a hurry.
12. My advice for this one depends on WHEN you shake/roll your bottles. If you're like me, and do it before even starting your manicure, you can shake. The bubbles will rise to the top of the polish & pop themselves by the time you get to the polishing stage, so it's fine. If, however, you do it right before polishing, them definitely roll (a tip - roll UPSIDE DOWN).
13. This is one I find myself correcting all the time. Your cuticle is THE DEAD STUFF; ok to nip off. Your eponychium is the living, protective tissue, and you don't want to nip that at all. Great detailed article, with a perfect photo, here.
14. For the first part of this, reread #13. For the second part, using lotion is fine if (a) you have nothing on your nails, or (b) you avoid your nails. Unlike cuticle oil, which is made to work WITH polish, gel polish, and any enhancement you wear, lotions have oils that work AGAINST those things. Sure, it'll moisturize your hands, but it will also seep into & under your polish/enhancement and can contribute to lifting (which all of you know, or should know, could in turn contribute to those icky "greenies" -- a bacterial infection called pseudomonas; not mold and not a fungus, btw).
15. While generally good advice, there are some exceptions. Fine grit files and buffers (usually anything with a number 400g or higher) will actually seal the edge when you do this. Also, filing back & forth on an enhancement won't hurt them.
16. As I started to say in #7... really ANY water is "nail polish's natural born enemy", as water (no matter the temp) will be absorbed into the nail and could expand & contract said nail, causing your polish to crack and peel. My best advice is to wait a full day after polishing to shower, always wear gloves when doing dishes, gardening, etc, don't use your nails to open/pick at things, use your cuticle oil religiously, and avoid lotion on your nails.
17. No. Just don't. Please. Non-acetone remover has so much other crap in it, and it takes so long to remove anything. Acetone-based removers are truly best (see this article). If you have more questions on this one, you should direct them to Doug Schoon, scientist & knower of most things nails. :)
18. This is true.
19. Definitely true (although I laugh because #17 *just said* NOT to use acetone-based removers on your nails, and this one says *to* use it...).
20. No proof of anything of the sort; these are marketing schemes, designed to make you think that those polish brands that DON'T label themselves as "3free" (currently, there are some marketing themselves as "4free" and even "5free", as well) are less healthy for you. Your nail plates are dead. Whatever minute amount of things you're absorbing is not getting into your blood stream. Nail polish, unless swallowed in large quantities (or if you're incredibly allergic!), will not harm you. Just an FYI - nail polish *never* had Formaldehyde in them; they had Formaldehyde Resin (completely different chemical make-up). This article may explain better.
21. Yes, use a top coat... always... One exception - there are some polish brands out there making one-night, easy off polishes; meant for a night out or some other reason for temporary wear (for instance, OPI made one, released as part of the Gwen Stefani 2013 Holiday set, called "Push & Shove"... base coat, two coats of color, no top coat).
My last bit of advice, if you don't want to do your own nails, see a real Professional, please. Stop going to those shops of "iffy" reputation & practices. You can always check out a salon or tech to see about their qualifications before your appointment either by logging into OPI.com, CND.com (there are many other companies have all techs who've taken classes by them, but not all -- for instance, I've taken two classes from Artistic Nail Design, but they don't have an online registry) or by checking in with your state board. You can also report anything you see inside a salon that you think is against state regs.