Ficus are aggressive growers that come from tropical and subtropical areas. There are more than 800 species of ficus, however, n bonsai some are more popular than others. Among the popular ficus we find microcarpa (Chinese banyan, tiger bark, ginseng, green mound) Benjamina, Macrophylla (moreton), religiosa (bodhi, peepal, sacred fig), and benghalensis. I have found these to be exceptionally hardy trees.
Soil: I have used many things as soil for ficus. I have rooted ficus in bark. Used all compost soil, and sand lava rock mixes. What you use really depends on where you live. What you want to make sure is that the soil does not get waterlogged, nor dry out before you can water it. For ficus anything in between will be good. Because ficus are aggressive they have a wider tolerance range. Of course the tree will do better if you find the sweet spot. In southern California we do not get much rain so i add more organic material to keep the roots wet during dry summer months. In Florida I, know people like lava rock and coarse sand because it rains so often that they need to drain the water out of the pots as quickly as possible.
Watering: This has a lot to do with soil. Yet, the basic idea is to never let the roots dry out on one end, and on the other the roots should not get waterlogged. Ficus as a general rule can tolerate drought. I have unintentionally ignored some ficus. They survived weeks in a 1x1x1 inch pot with no water. It did stunt their growth. So, do not try that at home. I would err on the wet side with ficus.
Sunlight: Full sun is the best. Ficus love the sun. Ficus will tolerate partial shade though. I would try to make sure that they get at least 5 to 6 hours of sunlight.
Fertilize: I fertilize once a week at full strength. Full strength is the labels recommended strength. I like using things with equal NPK (nitrogen, phosphorus, potassium). The plant knows what it needs.
Note: We are striving for the ideal growing conditions. Yet, for ficus we can fudge a little here and there.