Nothing is ever black and white, so the techniques that seem to work best for me I will try to relay as a generality as differing conditions require you to change on the fly.
Cat sailing is about leverage and hull speed. Turning your rudders at all presents added resistance to forward motion, plus the losses in trying to chnge dirrection. Therefore in general I find it much faster to attemp to keep from moving my tiller at all up wind. As I get tired this is harder to do and I find I am noticably slower and lower than I was earlier in the day. Anticipation of the gust is key to minimize how much sheet you are having to adjust to keep the boat attitude flat and constant. With varying pressure run your sail trim (and -very important- crew placement)to keep the boat in trim. With increased pressure you should let the boat accelerate, then let the lift of the foils ride the boat to a higher angle of attack. If you turn up with pressure before you accelerate, you will stall out the rig and foils, drop back down, have to reaccelerate again and end up being lower on the course than you were before, ususlly loosing at least 1/2 boat length in the process.
I typically sail with the jib. This need to be set up so the tells all stall properly, and then you can use it to watch whether the wind gusts are just preasure related, or if they are changing dirrection as well. If the dirrection is changing you can stear to it, if it is just a pressure change I do not steer.
Down wing ballance and weight seem to play an even more important role and there is quite a bit more tiller motion to maintain apparent wind, but it seams fastest when I can keep motion to a minimum. Always accelerate before turing, or if deceleration turn to go faster.
Unfortunately with the kids we are lucky to get out for the occasional race. More time on the boat alone or with a sparing partner is the best way to get better. My theory above is pretty general too and I do not ever manage to pull it off for very long, but we all need something to strive towards.
M
