I have been racing formula and longboards and course slalom for 24 years. Tactics aren't too complex when it comes to wind changes.
If headed upwind, generally ride out a wind shift to avoid two additional tacks, unless you need to tack anyway. If on the lay line, avoiding two extra tacks is really important, but as you near the mark, you may find that you still have to tack twice to make the mark. The decision to tack is best made near the mark, since a lift (wind shift) could bring you up to the mark when it didn't look like you would make it.
If heading upwind and sailing into a hole, generally bare off to maintain speed unless you can "read the water" and see that a tack will keep you in the wind.
Downwind, wind shifts are pretty hard to identify (see), but if you are losing speed, head up a little to maintain your speed (and plane), then make little adjustments back downwind if your speed stays up. If speed continues to drop when you were heading up a bit, you are either in a hole or the wind shifted significantly, in which case you gybe.
There are always exceptions to the above, especially if you are near a mark
For us average "Joe" formula racers, avoiding extra tacks and gybes is a good idea. Tacking and gybing are where mistakes are generally made, especially in windy conditions. Drop your sail once, and you are usually toast.
If it is really windy (20+ knots) and it is really rough, it's very difficult to see any changes in the wind (reading the water). Generally, you just feel it in your sail and you adjust accordingly.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.