Proper Foot Placement for All Surfboard Types
In terms of foot placement in general, the back foot must reach back over the fins to initiate turns. The front foot is usually in the center of the board, perpendicular to the stringer, with toes slightly pointed forward. This is the case on almost every kind of surfboard known to man. We make one exception for finless boards and boards called "hulls". I suppose I can cover those in another post. Suffice it to say here that this principle doesn't apply to them.
How to Improve Your Foot Placement Without Looking Down
It's good practice not to look down at your feet to determine where you're placing them. For this you want to go by feel and by video review feedback. You fix improper foot placement in two main ways: One, by refining your pop up at home and in the water. Two, by practicing moving your back foot forward off the tail block and back over the tail block both at home and in the water.
My Personal Surfing Stance and Why It Matters
What about me? I'm a neutral stance surfer who has a tendency towards my back foot. I can sometimes de-weight the back foot to get my fins out of the back of the wave, but it takes extreme conscious effort on my part. Putting any pressure on my right foot (that's my front foot) feels extremely unnatural and weird to me. That's why I look like such a kook when I'm trying to surf frontside in a regular foot stance! When doing that, I inevitably lean forward over my left foot because that is what feels most comfortable. Ok, I hope this is clear to you now! It might be a good challenge and good fun to watch surf videos and pro contests and try to determine which surfers are front footed, back footed, or neutral stanced!