One thing I have learned is that dormancy is a natural process, and plants grown under natural conditions of daylength will take care of these matters. If you are growing under lights, the gameplan needs to be a little different sometime.
Petiolaris complex plants have rather unpredictable dormancies, and if given optimal conditions of light, warmth and good nutrition do not have an obligatory dormancy. They will continue to grow, and should be encouraged to do so since losses during dormancy are frequent. Maintain them at 80-90F year round and they should continue to grow.
Drosera peltata is not a Petiolaris complex member. In this case, the plant usually starts growing in the cooler months in this hemisphere, and goes dormant as the temps. begin to rise (for me here it is middle spring). In this example, you need do nothing at all, the plants begin to wither almost overnight. Here the trick is to allow them to slowly wither away: too quickly and the nutrients stored in the leaves don't have the chance to be translocated back into the corm from which next seasons growth depends. Rarely, they skip the dormancy entirely and show little effect from it.
So the short answer is, don't worry about it unless it happens.
If it does, the Petiolaris need to be maintained at barely moist levels, and good air circulation is needed to keep them from mold attack. Drosera peltata can be rested dry (with scant residual moisture in the pot) or can be left in tray water. Be sure to mark the pot and spot since there will be no evidence there was a plant in it once it goes dormant so you can find it again next winter.
That's how you dew it.