Depends on your skill set and your opponents.
If you are a boxer and got fast takedowns you can always go for the takedown get a few hits and stand back up. You will have your opponent thinking takedowns. then you can fake a takedown and come in with a punch or W/E. If your opponent gives you problems striking take him down, if he's a JJ specialist keep teh fight on the feet.
ye well if I take someone down i will try to finish them right there and then. with a GNP.... ye if its a wrestler then obviously im gonna Box Him and move out the way but what if its some average joe mma club fighter and Im a Pro Boxer and I do BJJ... dont u think its best i run at him go for the take down and smash him with right and left hooks while hes down?