Roller size recommendations?

[Heather]

I've been using yellow rollers (3/8") since I started growing out my Louise Brooks bob. It gave me cute Marilyn hair when it was a little longer than that but now I look like a poodle when I take them out. I'm looking to upgrade. What size curler would you recommend for hair a little below shoulder length? I only do a basic 9 section wet set and pin curl it every night. I have red and blue rollers (not sure on the size at the moment) but they seem to give me more waves vs curls.