Storage is always a priority for my mobile base. Especially those cargo carriers. I like to horde.

First off lots of words ahead:

From all the bases I have made ( military outpost, firehouse, firelook, evac shelter, one from scratch) I take location into consideration.

So for example, in the current game I have a fire house base that is close to exodii and evac center, next door to a home improvement warehouse ( really nice when I started to build expansions as it has a lot of useful stuff and construction material bundles- got 200000 units of cement from the cement bundle), has potential for me to dig down and access the railway system and sewer system and since I cleared it out in year 1 spring, I have an easily accessible supply of a lot of random stuff from disassembly.

Since I have played around start near an evac center, makes a lot of material available and makes vehicle construction a lot easier as I can just trade some high value items and get most of my vehicle gear from Smokes ( welding gear, rods, tools, etc)

I found the firehouse is probably one of the quickest bases to get up to basic function, fairly secure as it only has one entrance room plus the 2 garage doors. It is limited on its funtionality and a bit lean on storage space it makes a fine compact base.

Military Outpost bases can be really secure as it only has metal door entry, and you can make your followers make a defensive trenches around the bases, also because it is built in the wide open you can see wandering hordes easier.

I find the moment I make an anvil, is the point where I can move from survive to thrive

Can't be near some really nasty things, like fungal towers.

Can't be near an area with a ton of enemies. Even if they can't get to you, it slows stuff like sleeping and crafting down. Some places have enemies at a higher z-level, like towers or subways, and they are a pain.

Underground area for dealing with portal storms and helping to mitigate temperature issues.

A nearby source of water is nice. Underground even nicer.

Scrapable wood furniture or fences or whatever is nice.

I always beeline the metalworking fab grind as soon as I have enough food to spend the time. Going from a few boulders, some wood, and a smashed car to a full set of metal tools is just satisfying to me.

Fridge, solar panel array, and blahaj. No home is complete without them.