I work out of a small van and dont have much space, leaning in and out of the van to get to stuff is a pain. My solution to this is have my most often used stuff stuck on magnets/or in easy to grab trays as close to the side door as I can get them. It depends on what you work on (I,m a Brit so mostly metric).
1. I have 4 combi spanners 10/13/17/19mm in a tray, I also keep a 10mm gearwrench
2. Side cutters/needle nose/combination pliers on a mag rail
3. 15/17/19/21 deep impacts on a mag rail/my Cordless impact and breaker bar live close by
4. a ratchet screwdriver and standard bits/torx/hex bits
5. My rechargeable LED lamp
6. Leather/copper faced hammer (this is all I use now)
7. I have 3 T handles with deep 8/10/13mm ready to go (I use these as much as possible for speed when removing pencil coils etc where an impact is too aggressive they are also great for engine covers and under-trays and the battery never runs flat
)
8. a small 1/4 drive socket set and a small 3/8 socket set (I keep a 3/8 spinflex with these and some extra extensions with wobble drives and 3 magnetic spark plug sockets
9. My DVOM with load-pro leads attached/DC current clamp/Midtronics
10. clic/clic r pliers and some of those hose clip pliers with a bowden cable to get at tricky clips.
11. I keep my set of 3 extra long needle nose pliers close by.
12. I then have a tray with various stuff I use, like tyre gauges/hub cap pullers/pry bar/thread file/caliper file/spark plug gapper/pocket screwdriver/wire brush etc.
I have lots more stuff on the van but I keep these items close by
