It’s obvious, that to play correctly your instrument should be tuned correctly. But what to do if your guitar goes out of tune too quickly. Check out some tips by maidenmyguide, K33nbl4d3, crazysam23_Atax, Nanobotter, HotspurJr, clayton.kardas, BlueGreen, clayonfire, T00DEEPBLUE and trashedlostfdup.
1. Aggressive strumming and incorrect spring tensions if you have a tremolo can cause your strings to go out of tune. Thicker gauge strings may require spring adjustments.
2. Don't tune with the guitar laying flat. Tune in playing position; it's both less awkward and, more importantly, most guitars will have a degree of tuning deviation just from the effect of gravity pulling the neck backwards or forwards. Tuning in playing position, clearly, means the guitar is in tune in the position you'll actually use it in.
3. Bends wouldn't throw your guitar out of tune, but heavy picking would. Seriously, learn to pick lighter. The goal is to pick nor heavier than you need to.
4. You might also want to add some lead between the nut and your strings (where the strings lay over the nut). Some tension gets caught between the tuners and the nut when you bend strings if your nut is not properly lubed.
5. The other one, of course, is how you wrap your strings around your tuning posts. Don't do knots, which not only slow down your string changes but make it more likely that you'll go out of tune. The key is you want three, smooth, complete wraps around the tuning post without kinks or more overlap than is absolutely necessary. Each wrap goes under the previous wrap, and they should be snug up against each other.
6. When tuning your guitar always end with tightening your strings. I learned in physics class that this will help keep your strings in tune.
7. Capos can put so much pressure on the strings that it pushes them down farther than necessary - lower than the frets and down onto the fingerboard. As a result, all of the strings will be sharper. Thing is, this is a problem I've only ever had with electrics. This generally happens with the spring-loaded capos. If it turns out that this actually is your problem, then you could try buying a C-clamp capo, the kind that screws to tighten.
8. If putting on the capo puts the guitar out of tune… then put on the capo, and retune. Takes a little more time, but it's pretty effective. This problem is pretty common, nothing severe; it happens. Not necessarily your guitars fault, usually the capo's. It's bound to happen.
9. A good Floyd Rose system should stay perfectly in tune after both divebombs and pull-ups. You should not have to dive the bridge to restore its tuning if its a Floyd. Ensure the strings are fully stretched in properly. Especially since you say they're relatively new.
Remove the bridge. Lube the knife edges a bit with Vaseline. If the knife edges are damaged, then that is very likely why it is not staying in tune and you may need to buy a new Floyd baseplate to fix the problem.
10. The cheap floyds are (almost) always a pain in the ass.