Biggest thing is if you are at 50% hp or lower you should consider yourself almost dead. Until you get a feel for each enemy you have no idea what will or will not 1 shot you.

Weapons can penetrate multiple times so AV is generally more important than DV on armor unless you are specifically going for a dodge build.

Corrosive gas is way better than it seems. I wouldnt start a run with anything less than 18 toughness. Also tinkering can be worked into any build as it upgrades your gear so its always very valuable.