For getting raw materials (metals) easily you’d need to mine a lot, or scrap it from planetary surfaces. The latter will work with a Sidewinder, Hauler, any boat, a surface scanner and a SRV (After buying your first SRV go to game options and set drive assist to off. Just turn it off).

Here’s how you do it: Jump to any system inside or outside the bubble, check if the first (or second, third) planet is rocky (not icy or gaseous) and surface scan it. If it stays blue after surface scanning, it has lots of raw materials. If not, it’s worthless and you can call it names (i.e. “rotten, useless bunghole of a planet”… just be creative) and leave for the next system/planet. But if it’s blue, go down, anywhere, as if you would land on it, but stay at maybe 100 metres altitude and fly over it at full speed or less until you’ll notice tiny signs of volcanic activities, lava, fumaroles. That’s where you land and jump into your vehicle.

Open your SRVs cargo scoop right now. Move towards those grey diamond icons, mark one by right-clicking (your gun will only hit marked targets), shoot it until the metal part pops out (maybe move around to get a better angle), mark that by right-clicking, drive over it to pick it up (your scoop will only get marked stuff). You did open your cargo scoop already, did you? You will notice the piceous cobble thingies will give you lesser materials only. It’s up to you if you dig those, too, or trade the more expensive ones for plain iron (etc) later. Careful around the wee volcanoes, they can heat-damage your SRV pretty fast. As the spot is “mined” out, drive back to your ship, fly a few kilometres, spot another volcanic area, land, get more mats. If you run out of fuel or ammo, synthesize it from gathered materials or just land on any space station/port and watch the vehicle getting refilled and repaired (space magic). Repeat until you’re ok with your success. Or bored. Or both.

Engineering is a main part of ED, and so is gathering all resources needed to make the most of your ships. I just restarted ED after a few years break, so I had to gather info how to do things post-odyssey. There you go.