After designing several malls, I have converged on what I believe is the best way to make one: the optimall!
It makes all buildings in the game plus logistics bots, drones and vessels and a trickle of warpers.
All produced buildings are buffered, can be sent directly to Icarus, and are ultimately provided globally by eleven interstellar logistics stations.
All materials are imported by eight planetary logistics stations and put on the logistics distributor network. (If your materials are on the logistics distributor network to begin with, you can delete the PLSs if you like, but do try to make sure that the materials can be grabbed from somewhere close by if you want a fast mall).
Unlike most other malls, all production is proliferated, providing a great boost to production speed and cost efficiency. There is no need to proliferate any input materials since the hub takes care of it.
The mall fits within the 25 cell wide band closest to the pole. The importing PLSs are in the 15 wide band within that. This means it's nicely out of the way.
Since it's mostly a bot mall, it is quite fast and doesn't take long to saturate.
It uses a crisp, modular, deceptively simple design that uses at most three logistics distributors per assembler. It is easily extensible if new buildings should be added to the game. Here is a separate blueprint for an uninstantiated mall segment that you can stamp down if you want to extend your own mall or even make one from scratch.
Initially, all buffer boxes and ILSs are set to minimum capacity; this is to help the mall saturate quickly. But you can obviously set all buffers to your taste; I imagine that you will want to increase the buffer size especially for high demand items like belts and sorters.
It takes a while before ILSs are produced, which can be annoying. The best way to deal with this is to simply hand-feed some produced PLSs into the appropriate input box for the ILS assembler.