At the end of your dive, when you finish your 3 minute 15 foot safety stop, and your ink pressure is pretty low (at least 500 PSI is what a lot of people end dives close to), before you head up to the surface...let the air out of your BCD. If there's not much sinking afterward, your weighting is probably about right. If you quickly sink, you may well be over-weighting.
You don't have to rush to be a 'weight nazi,' but if you can avoid being strongly over-weighted, your diving will probably improve.
Also, when you get down to a comfortable depth, get horizontal...and relax without swimming/finning. This will give you some idea of how well your weight is distributed. If you can stay horizontal without much effort, good. But let's say for sake of argument your feet sink and you assume a vertical, head up/feet down position pretty soon unless you swim along or make an effort to counter it. Then moving some weight from your weight belt or integrated weight pockets to trim pockets, or taking other measures to come some up your body, might help you more naturally maintain horizontal trim with less effort and have a better dive.
At least, that's my understanding of it, on matters I still work at. Be interesting to hear if anyone else here has a different take.
Other than that, book a trip and go diving. There's no substitute for that...
Richard.