Do you strop DURING the shave or only before and after?

One other question is, I currently have some shaving cream in a tub with a screw on lid. Vulfix Sicilian Lime. Should I still use a cup for whipping up the cream with the brush? So far I've just been dipping the brush in the tub. Been testing the brush and cream whilst still using a normal razor before I take the plunge with all the toys at once!