That's not an ideal watering method, and appearance is not a good indicator of dryness. How you water depends on the size of the plant and container, and whether the plant is kept indoors or outdoors. And, btw, you should find a non-metal container for it. Since you are container gardening, one of the best methods to use is the weight method - simply lift the pot a tad off the surface it's on and get a feel for the weight. The plant appears to want water at this point. It needs a good soaking. If the plant is indoors, try bottom-watering - fill a sink or bucket with water, then dip the pot in, without letting the soil surface become wet. Otherwise, run water from the top, allowing the water to run freely from the holes before turning the water off. Once it's thoroughly watered and most of the runoff has stopped, lift the pot and judge the weight - notice how much heavier it is after watering than it was before watering. This weight difference is what you want to go for. To know if it's dry enough before watering the first few times, you should let the leaves droop just a tad and then water. However, with practice using the weight method, you will begin to know when it's time to water before the leaves droop.