Swimming with fins

I would have no problem with using them here and there. Try to use a pull buoy also if you can.

That isn't going to solve your problem. Do a search on sinking hips and you should be able to find an answer to what you need to do to keep them up.

i'm surprised to say i have the exact opposite advice as some of the other posters.  the first thing my swim coach did when i hired him was tell me what i needed to bring to our first session.  it was fins, he preferred the split fin by tyr.  they are used for drills to help you concentrate on the drill and not the work of getting down the pool.  they help keep/make your kick more economical and strong. 

he is not a fan of kickboards, said they promote a bad kick (i don't remember the rationale) but he thought kick drills were better done on your side.  also does not promote the use of pull bouys, they hide a poor kick and bad rotation.

I'm no expert by any means, as my swim times would show. But here's my 2 cents. My understanding of the rationale against kickboards is that when you are swimming freestyle you should be rotating your hips. So you should be kicking on your side during kick drills to better train your body to kick in the same angle as you would during freestyle. Kicking on a kickboard trains you to kick with your body horizontal to the water, which is highly inefficient.