Boat control is critical to fishing success. It's often overlooked by novice anglers and even some experienced anglers. I find three tools indispensable to boat control: a bow-mount trolling motor, one or two drift bags and an anchor. Boat control is about positioning your boat in a way that optimizes your presentation. Various techniques require different amounts or types of control. Vertically jigging deep lake trout requires a steady or slowly drifting boat. I like to use my trolling motor for vertical fishing. The shallower the water, the quicker you can drift and still maintain contact with the bottom.
I use drift bags a lot while fly-fishing. When working flies deep and/or thoroughly a slow drift is essential. A drift bag will make a 10 or 12 mph wind feel like a 5 mph breeze. Drift too fast and you might as well be reading a book. Drifting is also a great way to cover water when casting or live-bait fishing.
Many advanced anglers overlook anchoring. When winds are too strong for the driftbags or trolling motor, or you need to fish a pinpoint location, an anchor can fill the bill. I like to use an anchor around 27lbs with a length of chain and 200' of rope.