Well, I just had a breakthrough* today, less playing wise, more tone/gear wise. I just moved back to playing 9s after a long time playing 11's and 12s. So when I play guitars that have strings thinner than 10s on, my sound seems to break up in horrible disgusting ways. This is most likely a problem totally secluded to me, but it's just that certain factors, in the case of me, combine to make it very hard for me to play with 9s and still have a nice clear sound. I think I've got it down to these reasons.
You may find it hard to get a good tone out of thin strings if you do the following:
-Pick very hard: I noticed that I have to pick notes at less than half of my normal picking strength when playing thin strings to get a nice clear tone. Gugh...
I suck. I'm guessing that it's because the strings flop around too much if I hit them too hard.
-Press down hard with your left hand: If I press to hard with this hand the strings go slightly out of tune, resulting in harmonic madness. I actually knew of this before, I don't know why I haven't thought to just press lighter. Ugh... I'm an idiot.
-Palm mute hard: I think you get the picture. All of these factors result in one thing: Notes going out of tune.
So if you have a hard time getting a nice clear tone, try using heavier gauges, or just play with more touch man. As for me, I'm abandoning all hope of playing with the touch of someone like Yngwie, I'm sticking to thick gauges.
Oh, and I want all you savvy instructors to stop worrying about me straining too much, I've been playing thick strings for so long that I'm not straining when I play fat strings and pick hard and press hard. Although I do recognize this as a flaw, and I'm going to practice applying just enough pressure to get the tone I want. But if you see any other problems with this please let me know.
(*Breakthrough: classified as when I go "Dude!!! How come I didn't notice that before!" all of a sudden)