The humble directional scanner is perhaps the least understood, least utilised, and far and away the greatest tool for PVP and moneymaking known to EVE. Well, it should be, but obviously 90% of people are shit at it, 9% are average, and there's the 1% like me who are guns at it and reap the rewards.
The directional scanner is a barely functional tool. The angle slider is clunky, the angles are arbitrary and can't be customised, you often have no idea in normal overview or solar system map exactly whre your cone of scanning is pointing, and the range is selectable only by typing a number in a dialog box. If CCP improved this part of the UI in any fashion, it would be a revelation for people in k-space as well as w-space. Nevertheless, if you have your shit down, you can get pew pew and bulk wads of ISK.
There are a couple of ways to get bulk ISK. This is only an incomplete list.
Firstly, you have to understand the little tickybox named "Use current overview settings". If you have set up your overview properly for PVP, you should have all the non-essential clutter of space filtered out. This should include a variety of things like POS modules, drones, wrecks, etcetera. Normally you won't see them and don't want them cluttering shit up because it makes it hard to spot threats inbound, such as combat probes or HICtors. No matter what the situation or where you are, always do a d-scan with overview settings off. You'd be amazed what you can find.
In nullsec, you will often find abandoned fighter drones. At 25-30M ISK a piece, if say a nyx has been scared out of a complex by some attack, and the drones don't warp back to the ship before he logs out, often they sit in space for ever. They can be found via combat probing (you have to set up a filter for drones to make this easy) and looted with a hauler. I scooped 12 Einherji last night; 250M ISK.
Nullsec areas where people have been fighting over sov can be awash with goodies aside from fighter drones. It is always worth checking for POS guns orphaned from POSs. Often what will happen is a sov-grind fleet bulldozers their way through a constellation, reinforcing POSs in ten minutes flat, and they ignore the guns entirely. The POS's RF timer is added to some embezzling nullsec warlord's gogledocs excell sheet, the fleet comes back, pops the stick, nd everyone fucks off to go ratting. Some die-hard idiots, being screamed at by the XO not to nick a fucking thing, then spend hours hauling orphaned POS guns. But someone didn't update their bookmarks. Enter the intrepid d-scan professional with a wormhole connection to nullsec; my best haul was 850M of faction guns.
Thirdly, you have to understand that there are several POS modules which are simply too big and too expensive to blow up. This generally includes jump bridges - you need a freighter to haul them around, or a T2 rigged orca at minimum. Because they can cost 150-200M for the module, and 50M in jump fuel to move, and a fuckload of effort and headaches, people generally pop the POS from beneath them and they get left sitting around in space. I know of five, so far, just chilling at moons; I lack the resources to steal them (T2 rigged orcas...ffff) but it's break-even for the first orca and after that, it's gravy. Cyno jammers, cyno beacons and so on are also often worth nicking.
Then of course, you have offline POSs. If you are ntending to be a salvage professional in nullsec, your best pickings will happen about 2-3 weeks after a major shift in sov. People, as I said, are notoriously bad at d-scan. You may have put your foot on 32 systems in 3 weeks, but no ne knows where the POSs are, and they'll de-fuel rapidly, leaving their tasty gizzards for the vultures. My best haul was 1.5Bn in moon goo, nicked literally under the nose of my XO who was ratting in system, then moved to hisec via a wormhole the next day.
So. How do you get 20B ISK in assets? In my case, not much via PVE.