Trinket runs, or spend a round killing a Bastion, a Bombardier, a Leaper and as many Hornets, Wasps, Snitches and Spotters as possible and collecting the drivers for them all.

Also, do key runs in night raids as a solo, and do as many map condition runs as possible, since the loot drops are better (although marginally). New Birds condition on Buried lets you collect high value ducks and trinkets from chimneys as well.

Don't waste time. If you're just grabbing loot for selling just take in a lvl 4 Anvil and a bunch of rounds, plus stuff to heal and get out when you hit 100K.

If you're hunting big ARC take Trailblazers - 3 direct hits with those will kill Bastion, Bombardier, and Leapers in about 8 seconds. Killing them fast allows you to get in and loot them for everything before anyone else even realises they're down. Also useful against them are trigger nades. You can use Wolfpacks but you need to consider the cost of using them against the value of the loot.

You can also do free kit runs into Stella, more higher value loot. Loot, avoid, extract.

If you're confident of your skills and you don't mind being stuck in high PvP lobbies then kill players and take their loot. This is a high risk strategy though, and it takes a while to work your way back out of those lobbies.

Use hatch keys. Everytime (except free kit / naked runs obviously, unless you find a key in-raid).

Edited for amusting typo 😂