A good toolbag, whatever your preference is. Love my Veto ProPac, had it a few years and have had absolutely no problems and I am not nice to that thing. Bummed around with all sorts of other bags but once I finally upgraded to a nice toolbag, I'll never go back. I prefer the backpack style but they have more typical style bags.

Multitool. I like my Gerber MP1 MRO. I've had Leathermans and they're okay but, to me, lack a ton of features that I use a lot. MP1 MRO has 1/4" drive screwdriver, all the tools are exterior accessible and the plier jaws are spring loaded which makes it more convenient for one handed use.

Same vein as the multitool, a good flashlight. I carry an ArmyTek Wizard Pro every day. Bright, magnetic base, good belt/pocket clip, battery lasts a long time.

Good pants. I pretty much exclusively wear 5.11 TacLites for the extra little pockets on the upper thigh for my knife, marker, pen/pencil, flashlight and the double knees are a must for me. I can't even count how many pairs of pants I've thrown away after wearing through the knees and having them rip to shreds. I work a decent amount of residential and occasionally do flooring work so your mileage may vary as far as time spent kneeling down.

Malco reversible 1/4 + 5/16 hex drivers and quick connect handles. A stubby and a long with their own handles made my life so much easier than having standard hex drivers.

12v screwdriver type drill like the Milwaukee 2401-20. Throw it in the toolbag, save yer wrists from all the twists and don't have to bust out a real drill for opening up cabinets, plus it fits in a lot of places other drivers don't.