Lisa dracaena: When watering Lisa check the that the soil surface is dry before watering. Checking for moisture can be a bit tricky with Lisa as many of them are potted in Lava Rock, which can be a very difficult soil medium for detecting moisture. For Lisa's in Lava rock it may be best to put them on a watering schedule, and keep a close eye that there is not excess water left in the plants liner between waterings.
The snake plant: tolerant of low light levels and irregular watering. As a matter of fact, during winter it only needs to be watered every couple of months! And NASA found the snake plant to be one of the best plants for improving indoor air quality.