For the Squamish bull trout, here are some good ways of catching them:
Find some slower waters and spin for them. Spinners and spoons that are 1/4oz are good. For this time of the year, find a school of spawning chum, spin behind the school, and you should be able to find a few fish. Those big bull trout are usually staging behind the spawning fish and feed on the eggs as they roll downstream. Colour of the lures... No specific preference really. I've found orange and pink have worked well for this time of the year.
If you are drifting under a float, a small piece of chartreus, yellow or white wool can work well after the salmon season. This may represent pieces of salmon flesh drifting down the river. We've also caught them on pink worms, blades, etc... They are more of a by-catch by steelheaders.
For spring time, back to spinning hardware again (unless you are a flyfisher, who would be fishing minnow patterns). The bull trout will obviously be feeding on small fingerlings.
Small 1/8oz spoons like a Gibbs Croc can be effective.