Mainly what I do with arks is sets of 10 back and forth for about 200-300 then forward only for another 100. If I do a progression it's usually just back and forth sets of 100-200 depending until finishing then 200-300 and maybe 200 or more back and forth and then forward only for another 100 lightening pressure in the final 100. I just finished a Wade and Butcher Special the other night like this and it rivalled the smoothest edges I've ever gotten... Oh! I also do some short push and pull strokes between every century set to smooth it out.