1. Check your weight. With an empty BC and holding a normal breath you should float at eye level. Add no more than 5 pounds to this to compensate for a full cylinder.
2. Pay attention to details in your pre-dive checklist. Include how much weight you used in other dives so you have an idea of how much may be needed in similiar situations in the future. This weight can also be a good starting point of weight needed for new dive situations.
3. Take a refresher class and work with your instructor on bouyancy and proper weighting. This can prepare you in advance of the actual dive with knowledge of what you need and can also help ease any worries you have which can affect your weighting.
4. Maintain situational awareness. If you notice a problem with someones weight. Mention something.
5. Use a line if you have control problems. You should be able to ascend at a proper rate without one, but if you are having issues on a dive, do what you need to in order to be safe.