Where do I put my front foot? I've noticed people's front knees at all different sorts of angles - are there advantages to different placements?

There is no correct placement for a front foot, it is more a matter of preference. Canoeing is an interesting sport in that there is no universal answer to the stroke of technique. You have some paddlers like Gab with a huge stretch to the front foot, others like Andrew whose knees are bent funny because they were born that way. It really comes down to what works for you personally. However, having said this there are two key things to think about with respect to your front foot; the distance of your stance, and where your foot is in the boat, in terms of side to side. The length that your front foot forward will help your overall stroke. Very seldom do you see extremely successful paddlers with their front foot very close to their block. Try and have a nice distance between your block and front foot. This will in turn will better set you up to incorporate the legs into the stroke. As for the placement side to side, the key thing to think about here is that your boat stays smooth through each stroke. For example, if your boat is dipping way to the right each stroke, and your front foot is on the edge of the boat on the right, you might want to think about changing it. Find a place that you feel comfortable with, and then put a piece of griptape down to help with traction. Hopefully this helps with your question, and thanks for the submission.