I found this method to be the quickest and most successful method of acquiring solar scorchers and alien blasters, but good cave loot also includes Brotherhood, enclave and NCR armors, bridgekeeper robes, hypo, and a few other useful things like police armor, drugs, g11s etc.
Firstly to do this you may need 300 sneak, but less might also work (this and outdoors are all you really need though), I simply have not tried. Secondly you will want to set your nowalls hotkey to something easy to remember (in Fonline2238.cfg file, under [Bindings] if not already there add; ToggleWall=Ctrl 9 (ctrl 9 as an example), and also the item highlighter mod available here;
http://forum.fonline-reloaded.net/index.php?topic=5681.0Another trick is to set your custom border to your max view range, as that is the range items appear on the floor to you no matter your facing and it makes checking caves a lot easier (having very high perception and agility helps alot too).
The concept is pretty self explanatory, but, try not to walk directly in front of NPCs (1 hex in their face) as they are prone to slap you and you will die, dont stand still for too long or you are likely to draw aggro and die, and when you are picking up gear keep your finger hovering over 1 to restealth if you become desneaked (which occurs at a pretty random rate) dont worry you get a few seconds if you do get desneaked, even when in plain sight. Also check under big items as multiple can spawn on the same spot.
Just take some leathers and a basic weapons just in case (or not) and set up a tent right next to one of the many "black patches" on the map, the shadow of small mountains, as caves have a good likelihood of spawning there.