My best suggestion: on washed/conditioned, wet hair, apply "Scruples Smooth Out" (one pump amount) mixed with "Scruples Serum", in a nickel to quarter size amount, throughout hair; blow dry with Infinity Hair dryer with ceramic straightening comb built in (awesome!); then run a ceramic Conair flat iron (red) with built-in comb on one side, as follows: lightly spritz a section of now dry hair with Scruples Urban Potion thermal styling spray and run the flat iron over it a couple of times quickly.
I learned this from my stylist.
I've tried everything for my "cat fur frizzy hair" and this makes it look like it's naturally straight!