Some things I've read or figured out over time, in terms of nail polish. c:
(I haven't worn it much recently because I play guitar, and strumming pretty much means all my polish effort gets wasted.)
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If you're planning to put color nail polish, put a clear coat on under it. This will prevent staining. Another clear layer on top of the color will prevent fading and keep it shiny and chip-free. It doesn't have to be a top/base coat necessarily, just something to protect your nails.
Light nail polish makes nails look longer, dark nail polish makes them look shorter. Clear is usually what I use - it goes nicely with everything, looks clean and naturally polished (ahaha.), has no stain worries, and it's nearly impossible to tell when it's chipped etc.
To fast-dry nail polish, put your fingertips in a bowl of ice water for about 10 seconds, then shake off. Repeat until dry to the touch. A blowdryer might seem like a good idea but it causes bubbles and streaking.
Don't pick nail polish off. You'll end up removing the top "skin" layer of your nails as well. Also don't apply nail polish if your nails themselves are dry/damaged, it'll make it a lot worse. (Foot cream works a lot better and faster than hand cream, to fix dry nails AND hands. It's greasier but you only have to use it once or twice to get the same results.)
Don't buy cheap nail polish. I don't mean price, I mean nail polish made with things that are BAD for your nails aka formaldehydes, formaldehyde resin, toluene, DBP, etc.
Some good kinds that are easily available and affordable: Essie, Revlon, Sally Hansen. Other kinds I've tried are Sephora, Julep, and Goldie, the bottles are lovely). My favorite ones I've used are Goldie, Essie, and Julep. I have a lot of Goldie nailpolishes that I got on sale at Bath and Body Works, but that was a long time ago and I don't know if that brand exists anymore.
(EDIT: From what I could find online, Goldie was a B&BW brand that isn't produced anymore. If I'm wrong somebody please correct me + source, I'd be glad to know - that stuff's great.)
To prevent streaking, make sure there's enough polish on the brush, then LIGHTLY brush it on in one stroke. Don't press down too hard, because that causes the streaks/bare spots.
Put nail polish EARLY. This ensures that it's got enough time to completely dry - I used to put it an hour before going to sleep and figured that would be enough, but nail polish takes MUCH longer to dry 100% so I would wake up with little cloth-crumple impressions. (I also incidentally broke my habit of sitting on my hands...)
A lot of darker or bold colored polishes will stain nails. For me, black nail polish doesn't stain, but blues do. It depends on its chemistry with your fingernails, and it varies a lot from person to person.
Rather than waiting to figure out if it stains/doesn't stain, it's best to prevent it at all. The best time to remove your nail polish is 3-4 days AFTER you put it on (so not including the first day you had it - therefore 4-5 days total).
An even more unwelcome effect is that your nails may yellow. This is because, like your skin and the rest of your body, your nails need oxygen - yellowing happens when they're deprived for too long. My nails tend to yellow/stain quickly, so I remove my polish 3 days after I applied it (total 4 days wearing) just to be safe.
If you do stain or yellow your nails, it can quickly be fixed. Just put some hydrogen peroxide on a cotton ball, and hold it on each fingernail for 5-10 seconds. (Don't get any on your clothes, it'll bleach and leave white spots where you probably don't want them.) This is obviously not the best thing for your nails, so see above for preventing it. And if it's a REALLY dark stain/yellow, it'll only fade so much - the rest you'll have to just grow out.
AFTER you've bleached your fingernails, however, DO NOT apply nail polish for at least a week (not even clear). They'll just stain even more quickly, so just wait for them to grow out a little bit before you get back into it.
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COOL AND PRACTICALLY-FREE STUFF. --> http://www.julep.com/
Just take the "style quiz", and it'll give you what color nail polish matches your style (the other options are on the bottom of the results page, in case you don't like the polishes the quiz gives you). Choose the one you like, then sign up for a subscription.
Enter either COLOR2012 or PENNY in the Discount Code box - this charges you only $0.01 with free shipping for the nail polish set! C:
After your package arrives, you can call and cancel your subscription (which is regularly $20 a month, there's a page that describes what they send you if you choose to continue subscribing).
(A Julep polish is somewhat expensive if you buy it instore, so this isn't half bad for what you get. ...actually, $0.01 isn't half bad for pretty much anything in general. |D)
NOTE: This appears to only work in the US as far as I know :c sorry guys!
2012-AUGUST-13 EDIT: The COLOR2012 and PENNY codes no longer seem to work. :c The new subscrip deal is on their website. After you go through the quiz, you can get
3 nail polishes for $9.99, PLUS 2 extra polishes free when you use the code they give you, which isn't bad at all.