The best thing you can do is take some weights and a mostly empty tank down with you to a pool/seashore and experiment. Where the weights should be added has many variables based upon equipment and body type, in addition to personal preference, eg What tank are you using, what weight system are you using (weight pockets, weight belt, weight harness, etc), body fat distribution, how much ditchable weight you prefer to dive with or none at all.
Only bit of advice I have that I think works or everyone in a drysuit is just say no to ankle weights if you were thinking of using them. Instead work on preventing gas from acculimating there in the first place, like with Gaiters.
