I would recommend "zoomers". They are fins that don't have a long "fin" to them. They encourage faster kicking rates and make you use your legs in a way more beneficial to swimming. Regular diving fins are meant to give you the most power for the least energy. You can make your own zoomers by taking regular fins and cutting off the ends a few inches past where your foot ends. Hope this helps.

TYR Split fin... great!

Weeman

So what part of your kick do you need to work on? Short fins are great for ankle flexibility. Long fins are great for making you kick low amplitude and from your hips.

 
Definitly Zoomers!!!

thanks for all the responses. Good question, Jill. I think the short answer is I just need to work on all aspects. So let me ask you (as I've read enough here to know tht you know lots about swimming), what is the better starting point? I know that I could definitely stand to increase ankle flexibility, but could probably also use more work kicking from the hip. So whaty comes first, or is it a "chicken and egg" conundrum (did I really just type "conundrum?)?

Zura fins

For both aspects, I'd go with the short fins, and then do a pretty high percentage of kicking on your back with arms streamlined.

If you're kicking from the knee too much on freestyle, you're bringing your feet and knees down too far in the water. When you kick on your back,you can't be bringing your knees up to bicycle kick like you can while on your front because you end up totally sinking if you try.

Jill, thanks for the response. As a follow up, when you say "arms streamlined," do you mean at my sides, or extended behind my head (which would be a leading edge)?

Darn it, Jill! I was going to say that.

DougStern

Streamlined is arms extended past your head with your hands overlapping each other and your upper arms squeezing against your head.