Do anything but dress your age.
Start with your shoes, really nice low key loafers with no bling. Italian preferably and black. Santoni is a name you can trust.
Next trou: forget jeans and think tropical wool and switch to linen when it's smoking hot. Very dark. Navy is your "Happy" color; otherwise charcoal or black. If you go black, you better go expensive, because cheap and black is almost always nasty looking. Again, Italian. See a trend here? Zanella is a name you can trust. Cuff them. 2" cuffs are the current rage and they have been stylish for over 100 years.
You wear socks? Make them expensive as well and silk or wool. Bresciani is a name you can trust.
Shirt? Simple, white or very pale blue or pink, and very expensive. Double cuffs with very simple Sterling silver or gunmetal links is the way to go. Borrelli is a name you can trust for the shirt and Tyrwhitt or Dolan-Bullock for the links. No need to go crazy expensive with the links, in case you are prone to losing them.
Positively no bling, Not even your belt buckle.
Belt? Black gator or croc would be rocking it, but ostrich or plain calfskin works just great. Simple silver buckle, never gold. Gunmetal buckles are also sweet when your links match.
Lastly, if you wish to be taken seriously, then a tailored sport coat is your admission ticket to acceptance. Never take it off until you get home or turn 30, whichever comes first. Make yours a relativelysmall pattern sport coat of navy and black; like houndstooth or similar. For off the rack expedience, Kiton is a name you can trust.
Here is the desired look for you:

This look will take you clubbing anywhere in the known world.
And do not be afraid of the uniform. Buy nice stuff, keep it clean, and wear it every night by swapping out socks and shirt for clean ones if you pull back to back all-nighters.
The only more sophisticated look for you, should be a custom charcoal suit with everything else remaining the same except for shoes where you could swap in some really nice black oxfords to finish the look. For the oxfords you may want to begin to look at English makes as well as the usual Italian suspects.
Cheers!
Oh, and you are not a promoter, you are "a man of leisure".
Edited by recondite - 4/17/12 at 9:23am