I recommend neoprene socks as well. I have some that stop at the ankle (like no show socks do) and they're perfect. I've never gotten blisters in any tail while wearing them I got mine on clearance at Big 5, and another pair I got on Amazon for cheap. Right now I wear 2 2mm pairs at once since the competitor monofin's smallest size is too big for me.

Just be careful with sizing when you order! I usually wear a 6 1/2 but the sizes that fit were 4 on one brand and 5 in another. Also I've had neoprene socks and water shoes that were size 4 and still say too big. So just be aware, read reviews on the product to see if there are sizing issues, and/or make sure the place you're ordering from has a good return policy.