Whats the key to a strong forehand with a mix of spin and flat?

Question

in terms of grip, body placement, and stroke

Answer 1

I find that a semi western grip, slightly open stance, and low to high swing motion will get you somewhere in between.  it also lets you be flexible in terms of opening up your stance and hitting with more spin or closing down and flattening it out.

Answer 2

I would develop two different forehand strokes.  One that you would generally hit at the baseline, with lots of spin, and depth.  And another flatter forehand to kill approach shots and winners when your opponent is out of position.

For lots of topspin, you would generally like a low contact point and follow through over your shoulder.  For a flatter shot, you'd like a higher contact point, and follow through across your body.