The setup is pretty simple: I have a Marina large Hang On Breeder Box, it hangs outside the tank and pumps water in via an air pump. I also have a secondary line from the return pumping a small amount of water via airline. I wanted redundancy to ensure decent flow and to prevent problems.
The last time I did this, I left out the stock air pump setup and just had the mod line from my return which failed & killed the fish while I was away - hence the redundancy.
I have a small length of PVC
pipe for shelter and that's it.
In tank boxes work as well, but I found the mesh ones became fouled quite quickly.