Both the above are bang on. Most my perching experience is on Simcoe however this train of thought worked last year on a kawartha lake for me too.
Year classes school together. If you get dinks, move. Plain and simple. Some guys have fished with me on the ice here for perch, I like to drill holes.
Most the time when you do get into true jumbos they are using a different bottom. Recently on Simcoe anyways, find some weed/cabbage in deeper water the better, the bigguns are around sucking in the shrimp.
For baits, I like the Lindy Darters and Powerbait & Gulp baits (minnows, fisheads and especailly the fish frys while they are feeding on the shrimp )