Know the mix
Dense compost holds water differently from a chunky, airy blend. Two identical plants in different mixes may require quite different checks.
Look at the pot
Small terracotta pots often dry differently from large glazed containers. Size, material and drainage all influence how long moisture remains.
Notice the room
Warm moving air, strong light and vigorous new growth can increase water demand. A cool, dim period usually calls for more caution before watering again.
Watch the saucer
A little runoff shows water reached the bottom. Pour away standing water so roots do not remain submerged.