ID. The drinking age is 21 and it is enforced at the door, including for people who plainly look older. Bring a passport or a driving licence; photographs of documents are not accepted.
Dress. Clubs on both sides of the bay turn people away for beach clothing, flip-flops, sports kit and, in some rooms, shorts on men. Wynwood is relaxed. Brickell rooftops are smart-casual and mean it. Little Havana music venues do not care what you wear as long as you can move in it.
Promoters and guest lists. A promoter's guest list usually means reduced or free entry before a cut-off hour, often around midnight, and it is a legitimate part of how this industry works. What it does not mean is a table, a drink or a guaranteed entry once the room is full. Be clear about which you have been offered.
Tables. Bottle service in a headline club is priced as a spend minimum, not a seat. Expect minimums that start in the hundreds and climb into the thousands for a good table on a Saturday, plus service charge and tax on top. There is no obligation to buy one to get in, whatever a promoter implies.
Book the thing that needs booking. Boat parties, bar crawls and any club with a named DJ sell out at weekends and during Art Basel week. Everything else you can decide on the night.
Getting home. Rideshare surges hard at 2am and 3am, particularly at causeway crossings. Budget for it, and do not plan to drive.