You can do a weight check at the beginning of a dive, especially in a trilam drysuit.
see to it that you sink when exhaling with empty BCD and drysuit but are able to stay afloat without finning or inflating either suit or BCD just by inhaling. Once you have reached this you add the weight of your breathing gas (1.2 kg per m³air at 20°C) in lead, this will keep your air bubbles small and you can adjust the position of your lead to achieve best possible trim.
btw I feel getting correct trim easier in my drysuit than when diving wet.
see to it that you sink when exhaling with empty BCD and drysuit but are able to stay afloat without finning or inflating either suit or BCD just by inhaling. Once you have reached this you add the weight of your breathing gas (1.2 kg per m³air at 20°C) in lead, this will keep your air bubbles small and you can adjust the position of your lead to achieve best possible trim.
btw I feel getting correct trim easier in my drysuit than when diving wet.