Scooping
On most ships, you can fit a scoop. As the name suggests, it allows you to scoop up stuff from outside your ship and store it in your cargo bays. You can even collect fuel from gas giants with the scoop; handy for exploring.
The Equipment
To scoop up anything, you are going to need the right equipment. Not all ships have a mounting for a scoop. To scoop just fuel, you can fit the fuel scoop. If you want to collect cargo from destroyed ships, then I suggest the tractor beam cargo scoop rather than the cargo scoop conversion. You can't scoop fuel if you only have the tractor beam cargo scoop. If you plan to scoop fuel from stars, you will need at least 1 shield generator.
Collecting Cargo
To collect cargo using just the normal cargo scoop conversion is fairly difficult. It's more suited to players who are very experienced in manual flight; the principle is similar to the tractor beam but requires a lot more precision and accuracy. As such, I will explain how to use the tractor beam.
Once you have destroyed all of the ships around you, turn on labels (press the 'L' key) and find some
cargo to scoop up—if you have a scanner installed, cargo will show up as blue items. There will be a lot of
Metal Alloys which are only worth about 20c/t, so look out for other things like Precious Metals, Gem Stones,
even Alien Artefacts. Once you have found what you want to scoop, set it as the navigation target, and start the
auto pilot (shown below).
Now you just have to wait as the autopilot flies towards the target. When you are near enough to the cargo, the tractor beam will catch it and put it in your cargo bay and the autopilot will stop as there is no longer a target to try and fly towards. You will see the following message:
If you check your cargo holds, you will now have a ton of extra cargo, free of charge!
Sometimes when you are in battle the tractor beam will scoop up cargo from explosions if they are near enough. If this has happened and you have a hold full of stuff you don't want (e.g. radioactives, rubbish etc) then just jettison it. You may find that it gets scooped back up straight away. If this is the case, slow down then jettison it.
Collecting Fuel
Scooping fuel is even easier. You can get as much hydrogen fuel as you can carry from Stars and Gas Giants, just keep an eye on your cabin temperature gauge—especially when scooping from stars!
Approach the star/gas giant you plan to scoop from at a reasonable speed, say about 750km/s. Aim for the horizon and use the 2nd or 3rd setting on the star dreamer. If you are successful in scooping, you will get a message in the bottom right, as show on this screenshot:
Each time you manage to collect some fuel, the star dreamer will go back to normal speed, so just keep your mouse pressed down on one of the other settings. Before long you should be fully loaded.
As far as I know, it is not possible to collect military fuel from any type of star or gas giant.