Have to agree with what's said above;
-Lots of salvaging nodes found in corusant in the sewers, and old market areas. Generally, they respawn every 10 to 15 minutes. (Maybe a farming issue at some point?)
-Salvaging levels super fast. Underground takes forever.
-Sort your armor tech by difficulty, then build the orange, and red items over and over again. (Green and Gray items dont really give any improvement on armortech skill.)
-Once built, reverse engineer the parts so you get salvaging components back to build even more items.
-Sometimes while doing Underground missions you'll get schematics.
With low level salvage materials you can buy them for as little as 1-2 credits per. On the more expensive stuff it can get pretty darn expensive. I'm at level 80 right now... and it's cool cause most of my manufactured gear is better than the items I'll get from quest rewards.
Also, the system is ALOT easier than it was in World of Warcraft. Which took ages, and you where stuck waiting in front of a retarded looking anvil staring at a progress bar.. :|