It really depends on so many things, including level, how good your serve is, etc.
Personally, I tend to go for bigger serves in dubs than when I play singles.
In dubs I'm looking to win the point on my serve, either service winner, or weak return that can be finished off at the net. That goes for 1st and 2nd serves. I'm willing to risk a few more DFs as a trade off.
In singles, I'm looking to get some free points off my 1st serve, but on the 2nd I am more conservative. I don't want to risk DF and am ok with just getting into the point with a slight advantage.