A pivot is used to turn a canoe that's sitting still, around its center point, and it's pretty straightforward.
To turn to your offside, you'll use forward sweep strokes. To turn to your onside, you'll use reverse sweeps. Although pivot turns work best if you're sitting in the middle of the canoe, if you prefer to sit on the bow seat facing the stern, leaning forward during the pivot helps you turn the canoe.
Something else to consider is, if you're paddling a relatively wide canoe, it helps to tilt the boat towards your paddle so that you can increase your reach for the sweep stroke.
As with all tandem maneuvers, pivoting require a cooperative effort. There are two ways to pivot a tandem canoe: You can use a combination of draws and pries, or you can choose a combination of half-sweep strokes. To pivot to the offside, both paddlers can use pry strokes. The other option is for the paddlers to use opposing half-sweep strokes.
In this case, the bow paddler with use a half-forward sweep starting at the bow and ending with the paddle at 90 degrees to the canoe, while the stern paddler uses a half-reverse sweep starting at the stern and ending with the paddle at 90 degrees towards the canoe.
To pivot to the onside, both paddlers can use draw strokes in unison with each other. The other option, again, is for the paddlers to use opposing half-sweeps. In this case, the bow paddler will use a half-reverse sweep starting with the paddle at 90 degrees on the canoe, and ending at the bow, while the stern paddler uses a half-forward sweep starting with the paddle at 90 degrees to the canoe and ending at the stern.