It depends on the brush. My '55 Rubberset 303 and JR#161 seem to work better with a painting motion. The rest do fine with the circular motion. I paint at the end to even things out.
I prefer the slap method ... I work up a real good lather in my wife's hand and then tell her she's just like her mother, then SLAP. It's applied with such force, that it gets really deep into the pores and all over my face. After that the hairs just about fall off my face and put up very little resistance. When I travel and my wife isn't available I use the SLAM method ... Very similar results of the SLAP method, but I use the door instead. Ask a silly question ... get a silly answer.
Thanks Steve! Have a good 'un yourself. There's a glass of rum and a cigar(Oliva Connecticut Reserve Toro) with my name on 'em.