In Amy's videos on this website, she writes that all increases are for the RS.
In Stitch 'n Bitch, the author writes that increases can also be done on the WS, but doesn't go into further detail. Hmm.
The pattern I'm working on asks for increases on the WS. Is there a particular increase I should use or should I purl twice into one stitch? And if so, should I purl into the back first, and then the front (as in the opposite of a knit stitch increase)?