Thanks for all the replies people! Some very interesting views.
Well I've decided to give salvage a go. I'm not quite going Iron Man mode - I don't feel like I'm cheating anything by taking out ship insurance. I'm taking no missions and I'm not looking for combat. New ships will come by way of whatever salvage I sell and whatever small amounts of exploration data I collect as I hop around.
So far I've tackled USSs in my home system. Unpopulated systems have only offered Degraded with mats in, no cargo at all. Low Security, Boom state, not found any loot there either! Hopped over one system to Anarchy, no state - dropping into Threat 3 Degraded has offered up some tasty loot with that strange single Painite floating in the middle of a spread of leather and other textiles... a few of those has gotten me into an off-the-shelf Cobra III and managed to pop in some bigger cargo racks. I have since found another Degraded USS with a cheeky Painite in it but not many Threat 3 going and those I've found aren't all offering loot. Had to scoot away from pirates twice, but I guess that's no challenge at Harmless combat level, even in a Sidey with E-class thrusters. So this evening (UK) I'm surface-side in an Anarchy system and having way much more luck (and fun). I've landed, picked a direction and stuck to it. I've found a couple of mining sites and a couple of stashes guarded by skimmers. My route took me through some rocky terrain and my ship wouldn't land close so for the stash found in a small ravine I've had to do a lot of to-and-froing just to load up the loot. Found one Narcotics and one Taaffeite, the rest not really worth much but it'll all add up! Spent about 4 hours on the surface and just about to go sell my goodies.
USSs may get a little monotonous unless I can find a pattern of security levels, allegience, state etc that offers up some variety. When I only have a bit of time to play, I'll scour USSs. When I have hours to play, I'll be down on the surface.
I'm not looking for fast credits, completely the opposite. My current loot is worth about 150k but I doubt I'll get that at the market. That's rubbish for 4 hours play, and I'm happy with that. I should be in the Cobra for quite some time.