If you're going on vacation for a few days and don't have a way to keep your indoor plants watered, you can actually keep them alive with some paper towels and a glass of water.
We've shown you several ways to make an automatic plant watering system in the past, but this technique is the easiest and quickest we've seen yet. Simply roll up some paper towels as tight as possible without them breaking, dunk the ends in a glass of water, and lay the remaining across the soil so that each plant is at least a few inches away. The paper towels will absorb the water from the glass and spread it evenly over the soil. The key is to make sure the end of the paper towel is as deep in the glass as possible to ensure adequate watering. The deeper the better.
We haven't tested this one ourselves, but a quick Google search reveals that this is actually a pretty popular technique—so we're confident it would work well if you don't have an automatic watering system already in place.
Plant Hack: Watering plants while you're away | Andy Shora