When i troll, I always store the location I get fish at. This is a good way to find jigging locations. Same goes when you see other boats catch fish. I use a spinning reel with 20# spectra (power pro, etc) with a 4' or so 30# mono top-shot - heavier mono make the mono-to-braid knot stronger. The jigs i use tend to be in the 4-6 OZ range. I like the Mega Bait holographic jigs & so do the Springs!! I always ditch the treble & use a 5/0 Mustad 95170-SS Siwash hook. I usually cast "downstream"; the direction the boat is drifting in. How far i cast & whether or not i feed-out some slack after the cast depends on the depth I wanna jig at. If your lure has drifted much past being straight-down you will not get the proper fluttering action & you must reel-in & start over. Let the jig drop & jerk it 3-4 feet every 4-5 seconds. They usually hit on the drop. Watch your line at the rod tip; when they hit the line will stop before it should - strike hard. With the high retrieve rate of a spinning reel, I find a 7' or so rod is long enough to always be able to keep pressure on the fish - make jigging much easier.
As for colors, something with green is always a good choice. Although not a mega bait, i found a blue/pink/white 60z Point Wilson Dart Candlefish to be hot at the banks off Ucluelet/Tofino.
Since the strikes come on the downfall & your line must be slack for the jig to flutter, don't pull-up too far on your jerk.
The Canadian Princess boats out of Ucluelet (History now) had some good (and bad) techniques. They had great Furuno sounders & never bothered to stop unless they were marking Salmon. They always jigged at the same depth as the fish. These days the new CHIRP sonar's let the rest of us have great sounders.