Gather all of your plants in the bathtub and drench them with a shower from above.
Then, fill the tub with 3 to 6 inches of water (depending on the size of your pots) and cover everything with clear plastic (even a clear plastic shower liner works in a pinch).
This simple setup helps keep up humidity levels and lets the plants wick up water from below, buying you about two weeks of vacation time without worrying about your plants drying out in your absence.
Ideally, you should shower your houseplants twice a year in spring and fall (after the harsh environments that a dry winter and hot summer can create for indoor plants).
Gently run the water over your plants for at least 3 to 5 minutes, making sure to rinse the tops and undersides of the leaves and saturate the soil until water drains freely out the bottom of the pot.