How would I start working towards that?
First, do a search here for as much info as you can gather on ficus. Second, while not in English,
this guy has a TON of videos on ficus, and his methods worked very well for me.
On your tree, you are closer than you think on accomplishing that design. That blue area I marked needs to be carved up (remove that dry stump away from where the last chop on the tree was performed) into a nice transition to those leaders. Ficus grow extremely well in FL, so I wouldn't put this into any over size container as you will loose the tightness that Wigert's already created on it. You will need to wire a few of the branches you have now if you want to conform to the more traditional mini tree, but you have a nice broom shape... do some search and decide which way to go.
I would suggest buying
cut paste to cover the area once you carve it, you need to have live tissue all the way around it to heal nice and quickly. I have used refrigeration clay, and it works ok, but that cut paste will accelerate the healing. Ficus heal fast, but with the paste its stupid how faster they will heal a trunk chop.
If you can afford it, get a Mirai membership, do the free trial, if you like it stay for as long as you want, if you don't cancel and they will not charge your card. I did the trial thinking about cancelling it and I am still a member since 2019. There are other channels, but the library they already have is well worth the money vs the other ones.
I think this is the best side of your tree, I would repot this summer into an oval container or the same one you have now exposing a little more of the nebari to help it flare out more.