Another thing I've been thinking about.

If you have the decision between:

A) Take the trip (even if it scares the hell out of you), or
B) Sit around home for the next couple weeks (or all summer),

Take the trip. Which are you more likely to remember 20 years from now?

And do guys need to dress down? :?

NObody needs to dress down imo
:-) At least not for traveling in Western Europe certainly!! If anything, doesn't hurt to dress UP a tiny bit.

Now back to Lea's suggestions above, if women are traveling solo to places that are or are perceived as dangerous or culturally so different you need to not wear makeup and cover your hair... this may be valid, i'm not certain, just nothing I have any experience with. Maybe it's because I am now an older solo traveler (not a young hot babe) people don't bother with me much.

I would think that if you are going to a place where it is wise to not wear makeup and/or cover your hair, that you are better off trying to duplicate their attire rather than just dressing sloppy, etc.

I also agree that in most places it is better to dress up slightly than to dress down.