Modern Stag & Hen Customs
Nowadays the "night before" bachelor/bachelorette party is far less common than it used to be. Instead - sensiblty - most people allow a sensible "recovery period" between the party night and the wedding itself, at least a week preferably a fortnight.
Vacation
A stag or hen party used to consist simply of the participants visiting one or more of the local bars and clubs. Today it is increasingly common for the whole party to go away from the home city, perhaps for a weekend short break. Often the group will buy specially printed T Shirts, hats etc to mark the occasion.
If you wish you can buy a complete party package and book everything in
advance rather than relying entirely on the poor best man or chief bridesmaid to organise
it all. Sometime
these will be based around a particular theme and a whole industry is growing up around
organising professional stag & hen parties.
Some places seem to have become centres of attraction for pre-marital parties. In the US Las Vegas is, of course, popular. Here in the UK Edinburgh is becoming increasingly popular as I've seen for myself on many weekends.
And yes, even in these PC days "risque" activities are still common...
The stag and hen party should be fun for all concerned. Try to retain some
semblance of self-control. What seems like a great gag or practical joke at the end of the
night might seem rather less amusing if someone wakes up the next
morning in a police cell or hospital.