You really only need to fertilize your figs once a year if they are in the ground. Fertilizing them too much can keep them from making fruit or even kill them if it is being applied super frequently.
Mine are potted, because it is watered more often and the nutrients are flushed out I fertilize them three times a year. One in the spring with the fish emulsion (Alaska brand, as recommended above) and then at the beginning and end of the summer with the (Alaska) blooming fert and fish emulsion, respectively. Both are liquid and water soluble.
They have gotten bigger and stronger every year with lots of beautiful green leaves, but little fruit. Figs have a very long juvenile period, so you just have to wait it out until the fruit comes, in zone 9 that could be 4-6 years, depending on how severe the summer is. When the trees were immature I only gave them fish emulsion because they tend not to set fruit at all the first three years and then the fruit doesn't ripen the next year or so either because the tree is vegging too much to send it's energy into blooming and ripening.
After my first edible harvest (5 years) they have set fruit reliably, increasing the yield a little each year.