what makes someone appear desperate?
torso pics, then being constantly messaged when your answer clearly shows your not interested. Believe me, if I was then I would tell you ! Sounding too good to be true...
what would turn you off someone completely ?
married/attached, having my profile constantly viewed by the same guy daily turns me off to, people who obviously love themselves and it shows in what they write, it's not sexy and it makes me want to

what should you write in your profile?
be completely honest about yourself and what makes you tick, it won't appeal to everyone, but it could appeal to the right one. Have up to date pic as your profile shot too.
what sort on introductory message would get your attention?
short, imaginative and fun
what words are best avoided in a profile?
'tell you later'... I won't bother asking later then, it wreaks of can't be bothered or best get rid of my fella/ lass before I get interest in my profile.... Putting yourself down too... don't do it ! If you were selling a used bike you would talk about its great features and skim over the not so appealing parts. Take the same approach to yourself and let your date decide what they think. You never know, they might just like you.