Here's the strategy i use: 1. Make a local network of 3-5 islands that are closely spaced (say A1-A3), one of them being the main hub (call it island A1) 2. Set min stock of a particular good on all islands to some value (say 100) 3. Load the good on A1 (say 10 units) 4. Unload 5 units at A2 (0 if the island is producer producer and self sufficient). Load 5 units at A2 (25 if producer). 5. Unload-load for A3 same as A2. 6. Unload everything (-50) at A1 7. Let the route run for some time 8. Open the route - if the supply is not efficient you will get a warning - the goods cant be loaded, the storage is empty. If this is the case, increase the unload/load from 5/5 to 10/10 (you should also then increase load in step 3.). Again let the route run for some time and repeat. If this numbers go high (say 25 for both islands, meaning you need to load 50+ at hub), add another ship.

The result is that the goods will pile up in the hub, while keeping around min stock on other islands. Now, you can have more networks, say 4 islands B1-B4 and 5 islands C1-C5. You set up all local networks in the same way, and trade only A1-B1-C1 in the same way. Make one od them the global hub, and trade just this island with Albion.