all these methods are fine. i use a combo of the pot weight, plant visual, and moisture meter. the moisture meter is actually more useful for watering bone dry plants than it is at telling you when to water. ever notice that the first bunch of water leaks right out of a bone dry plant even if you water real slow? the meter lets me know when i've actually eliminated all the dry pockets. nothing like running 2 gallons of water though a 3 gallon pot and still having dry pockets.