I don't fast travel, but I do have the maxed Lone Wanderer perk and 2 Ranks into Strong Back. Also, full Deep Pocketed Shadowed Heavy Combat Armour and a decent level of STR.
I don't use companions either, but I have every non-faction related Settlement unlocked, and Jamaica Plain was my last and is still in the process of being constructed. It's location is immensely useful due to it's proximity to several resource intensive places.
Anyway, a good amount of my carry capacity is taken up with my weapons and armour, but I'll start picking up less things after I've fully constructed a defensible outpost/settlement at each location.
For example, Outpost Zimonja will get a smallish shack for my needs and the rest will be defensive walls, turrets and guard posts. The Starlight Drive-In however, will have separate sectors for myself, farming and residential. I could really do with an increase to the Settlement size limit there tbh, and the option to either bury those skeletons or boil them up for oil.