This, of course, excludes most toddlers. Good taste in clothes. Gay men are known to have good fashion sense, but keep in mind that guys with girlfriends who dress them also dress well. Some people believe that in a gay relationship one person plays the girl part and one person plays the boy part. This is true some of the time.
Many gay men can be very feminine.
Many gay men, especially drag queens, get their nails done. However, my middle aged ritzy very straight father does too, as do all his straight golfing buddies. I have never heard this voice on anyone but a gay male. Very often if someone embodies all of these elements, you can be pretty sure that he's gay. But, remember, straight men can have all of these characteristics as well.