Personally
Yes i agree you should be there earlier to hear the preceding music
But disagree strongly that you have to follow the last guys style.
Main reason for being early is to avoid duplication and also similiarity.
For example the last guy finishes with twenty minutes of well known oldies or modern.
A good DJ needs to introduce himself, get the crowds attention and go for it.
Trying to be different myself i usually start with an instrumental.
If its an upfront crowd. usually Joey dee how can i forget
Mixed crowd. The Dogs Soul step
Oldies/handbag crowd. Six by Six
followed by a biggie or an oldie depending on the reaction (usually sixties)
Anything from Damon Fox, Joe jama, timmy williams, Magnets (rasel), Joann courcy, The Martells to Gwen owens (velgo)
Its up to them to keep up with me after that