You'll see a lot of different opinions on # laps for stropping, but all will say you need to strop before every shave. I do 20 laps on the webbing, then 50-60 on leather. Nobody seems to know the min number of laps needed on the leather, but since you can't "over strop", it does not hurt to do more... so you'll need to experiment to find what works for you and your particular razor.

Some folks strop after shaving to clean the edge, I don't, but I do "strop" against a piece of tissue with some mineral oil on it to ward off corrosion on the edge.

-Chief