I've played seeds with full blown portal hubs...but my recent endeavor involves simply numbering each portal I drop. I'm currently up to 17. I keep one Portal in my main base, that I simply change the number on, to determine which of the 17 portals I go to. I have a 2nd portal in my main base that remains unnamed. That one is always on the ready for a retrun trip from anywhere I drop a brand new portal. So lets say I've wandered too far from the most recent portal I've used and need to get back. I just drop a brand new unnamed portal that connects to the unnamed portal in my main base. I go back to my main base. I then rename my "Variable" portal "18" then go back through the unnamed portal... renamed the unamed portal "18" and voila. I'm back home again, with 18 portals.