Set your sails and steer in the groove between powering up an footing off. For me it is more about feel. Try to keep that groove without killing your power by footing off too hard. If you are surfing down waves, you may be able to foot a little harder, but power back up before you bottom out.

As far as setting sails, it depends on the boat. Spin boat, travel in to center.... others travel out just past the strap. H16s like to really let off on the mainsheet to give it more more twist, but I like to sheet it in a little tighter like I did when I sailed H20s. Lot's of H16s like to foot as hard downwind as possible, but I think it pays to power up a little and keep that apparent wind working for me.

Not sure this is right... but it's worked for me plenty of times.