If your going to be traveling the stars, then your going to come across a crashed ship from time to time or a derelict a drift in space. If your running a salvage crew as the captain then your going to have to look for work everywhere you can so you end up looking at all the reports of every lost or missing ship at every star port or base you come to and their last known location in hope for a score.
Hit the bars for rumors of missing ships not reported, so talk to other trader ship captains some traders like to travel under the radar so to speak when their carrying cargo let's just say that they don't want to be caught with. Great to have a few smuggler friends to off load that kind of stuff quick but cheap.
Plus if there is any clashes going on then there is a chance for an even easier score just don't get caught in the middle between the two clashing sides, best way to find this information is to find young marines, sailors and soldiers in the bar and offer to buy a few drinks, older veterans and officers know better to not to talk about such things but younger troops want to brag about their heroic deeds of battle and where it happened.
Large battlefields are littered with equipment that was either damaged, destroyed, just plain lost, or just left behind due to cargo space, not everything is broken or wasted, most military campaigns just keep moving on and pretty much just leave broken or useless equipment behind, nice stash of weapons, ammo, firing computers, comms equipment and a like can be found. Lots of fair size colonies feel the need for such stuff to protect themselves and you can get a good price for your stuff there.
Talk to Scout ship crews, they come across derelicts drifting from time to time and fail to report them, either by accident or on purpose for a score of their own, and a few drinks will help loosen them up many times. What the crew knows is not always what the captain puts in to his ship's log.
Working ship parts and ship's equipment cost a lot of credits, and one can get about half as much for them, depending on a lot of factors working or needing some repair, but there is always a buyer somewheres for what you find or recover, so make sure you have a long list of potential ship builder clients. ship building yards are good for buying engines, jump drives and ship computers of all kinds to cut cost of a build or repairs to save time for new ones to arrive.
Avoid areas where pirating is going on, two bad things can happen there, either you get hit by pirates or the authorities hit you for being a pirate. Unless you know the players on both side in that system and they know you but be warned you'll have to play both sides against the middle, because both side will want you to throw them a bone from time to time.
One of the last jobs you want to take on, is to salvage a failed colony, it's sad when you know that these were families trying to make a fresh start and fail, many personal items are left behind to remind you that this was once someones home and life, it can make you feel alone and lost in your mind sometimes thinking this could have been your life. Better jobs are old refineries and mining operations.
Why be on a salvage crew, why not be a belter working on some asteroid or working with a demolitions crew on some city world revamping some city block, work is steady and so are the hours, and life will be the same day in and day out and a rut, for me a salvage crew seeing the stars and other worlds, my live in my hands and hold to no man but me.