Thank you OP for this thread! I have about 10 dives in my Fusion and another 12 dives in a tri lam. From the get go I have struggled with buoyancy, made even more frustrating by the fact my husband has no problem!
We have worked hard to get weights correct being a natural floater but we also dive more fresh water than salt water so have to keep changing.....During my dry suit course I had several feet first ascents which are scary - consequently I really dislike the "floaty feet" sensation. was doing well until got in a current situation and lost buoyancy feet first. Luckily my husband/buddy was very close, grabbed me and also spotted a 8 lb downrigger ball which he handed to me and I was able to get down and reorientate myself.
Like you say it is practice, practice , practice.