Watering cans come in every shape and size imaginable, but without doubt the best kind available on the market today is the type with the long thin spout which is pictured here. It is particularly useful in watering around the base of plants whose foliage should not be wetted, such as the African Violet or Saintpaulia.
A good indoor thermometer while not essential is helpful in letting you know just what the temperature is at the location of the plants, and how much of a change they have to endure at night.
For the gardener who plans to start plants from seed, the dibble is an instrument designed to punch a hole in the earth when transplanting seedlings. A dibble, or dibber as it is sometimes called, is a luxury rather than a necessity, and is only really useful if you are going to do a great deal of planting. In any case, a sharp pencil will do the trick in nine cases out of ten.