Step 1: Watering
A simple way to test your water levels is to stick your finger into the soil. If it’s still moist then leave it alone, if not then water.
Always use warm water, not cold. How would you like to take a cold shower in the morning? Some plants are more sensitive than others, and can get easily shocked by cold water.
When watering, water just the soil and try not to get the leaves and flowers wet. Sometimes this can cause rot and sunlight damage.
For house plants, it’s beneficial to mist down the entire plant during the summer just to wash off any dust that has collected on the foliage; kind of like taking a shower.
Also for indoor plants, place a saucer underneath your pot to catch any excess water that drained out to prevent your furniture from water damage. Also pour out the collected water to also prevent root rot.
Of course, different plants have different water needs. Some are drought resistant and others aren't. Do your research and find out what your plants’ needs are! :)