Does trying too hard with your appearence turn-off guys?

I disagree with other users saying that there is never 'too much'.

Some extreme examples of this are things like anorexia and bulimia, both are, in part, a concern of ones own appearance. While admittedly these are extremes, they are definitely 'too much'.

I know that I personally am not a huge fan of overdoing the makeup, jewelry, or god forbid, going crazy about making your nails look a certain way. While some makeup looks good on a girl, used to accentuate themselves and 'polish the rough spots' (we all have them)
and I must say that on the right girl I'm a very big fan of dark eyeliner around the eyes.

In my opinion, however, blush, lipstick, or pretty much any form of makeup can go over the top. Im really not a fan of boldly obvious eyeshadow (its shadow, not highlighter after all), or lipstick at all really.

Its hard for me to give you a concrete line about where to stop trying to improve your look, but I think the 'less is more' statement comes close. Anything over the top makes me blanch, so just try to be mindful?

It's never too much, as long as you're always confident in how you look. If you feel comfortable with the image your give off and feel that it's genuinely you, guys will be attracted to your confidence. I believe that you can pull anything off as long as you do it confidently. So don't wear clothes/makeup/etc. That you're not sure about, because guys will pick up on that and you'll look/feel wierd, even if it's not that bad. So always be confident in what you do and be yourself!