So why Ficus?

Most of the bonsai I use are Ficus retusa for the following reasons:
Grows fast
Loves the heat
Can be grown indoors
Very forgiving
Grows fast
I can start a cutting early in the season and have a GORGEOUS little bonsai by the end of the season. I give miracle grow at full strength about once or twice a week during the spring and summer. When wiring, you have to be very careful or the wire will embed very quickly. However, ficus will grow in wiring scars in a short amount of time.
Loves the heat
I keep my bonsai outdoors year round. As long as I keep them watered and provide plenty of shade during the HOT (+115f) summers here in Phoenix, they do GREAT! In a way, the cooler winter months are the worst for my ficus. Have to protect from frost. Most winters, this is not a problem in Phoenix!
Can be grown indoors
Let's face it. Most people want a bonsai that they can keep on their desk or somewhere indoors where they can appreciate their beauty and charm. You cannot keep temperate trees indoors. Ficus are tropical trees and can tolerate a lot of conditions that would be murder on a normal temperate tree. Which brings me to the next point
Very forgiving
Make no mistake, ficus love lots of heat, light and water. They are tropical after all. But not all tropical locations have a lot of light or water. The canopy in a jungle can be quite dense. Ficus will tolerate low light levels. Ficus retusa (unlike F. benjamina) do not drop their leaves when moved to lower light conditions. Their leaves will darken. I believe this is an effort to compensate for low light levels and should be taken as a warning to increase light. They also store water to some degree in their trunks and have waxy leaves. This means they will not dry out so quickly if you neglect to water them. Alternately, they will not complain if you leave them in a container of water for a few days - like say you were going away for a week or so and wanted to be sure they got water. You can leave the pot in water for about a week with no root rot.