given that you have set the trim correctly the best wisdom is not to pinch and not to give to much head. You will need to run against your opposition a few times before how far off pinching is fastest. Not pinching takes a while as you feel like you are not heading as high as you should or can. IT is about VMG though. There is a comfort that comes with pinching in that the boat remains under your control and feels safer to some people.
I find there is a moment when the boat sudenly feels happier as I come off the pinch. IT settles, surges and feels powerful.
In a gust that won't stay trim give a little sheet and bring it back in to pump as much of the power into the sail as you can before loss of trim.
Get strong and pump the sheet until you have to let a little traveller out.
Lazy is slow.