One of my favorite styles for tropical bonsai is the exposed root style. This may represent trees whose roots have been gradually exposed by a river washing the soil away from the roots or with trees growing on a hillside which is being eroded away. It also could be the end stages of a tree starting life as a strangler or epiphyte and then having the host trunk die and rot away leaving the strangler exposed by itself.
See how these various figs in this style work for you.
The definitive reference work on Ficus
for bonsai. The book is a softcover, 8 by 10 inch volume, with 144 color pages, containing detailed information for the beginner as well as the advanced hobbyist.