If you get a chance to play Expedition 19, Voyagers, while it is still active or returns for a redux session: This one is a nice introduction to corvettes, a great way to learn about their game mechanics and a fine opportunity to collect a variety of corvette pieces as rewards for expedition objectives. Complete the expedition to your liking, so you can unlock the ability to transfer items back to your main save. But don't end the expedition yet, as explained in the last step of this guide.

If you enter the expedition late, don't worry: You can still apply the concepts described in this guide without completing all objectives in time. Also, the scrapship method should likely work with later expeditions as well, although the resource costs for applying it might well change.

Collecting corvette parts is not difficult, but it quickly gets repetitive. Getting a larger collection of pieces can take a while, e.g. if you wish to keep several detailed ship designs. This guide is about reducing the effort to get there, while using the available game mechanics to enlarge your collection.

But first, let's look at the least cumbersome method to collect a few pieces. Fly near the surface of a planet with Salvageable Scrap, which is shown in the planet's information summary whenever it is present. Step back from your pilot seat and use your visor to look for the yellow icons of the scrap pieces. Once a site is marked, the hud marker remains even when you get back to piloting the ship. The ship's board cannon system will quickly destroy the buried modules, which allows you to collect the scrap without ever going down there or digging into the ground. Weapons with more spread, like the positron ejector work even better for this.

Once we have a few duplicate corvette parts, we can head over to any space station and exchange them at a corvette terminal. When doing so, you are presented with an acceptance probability, which reflects the relative value of the pieces you offer. There is no penalty or limit for refused offers: You can just try different combinations of pieces until the trade is accepted. Note that even when the displayed probability decreases as you swap out some pieces, there is still a fair success chance, unless the value drops way below 20%. This way, we can add more interesting things to our expedition collection, with the goal of having one piece of each variant we want to transfer.

Now we get to the point: What is a scrapship? At the end of an expedition, players typically attach as many parts to their corvette as they can, since copying over the ship to your main save is much more convenient than transferring the pieces like other items at the terminal. And some players realize that you can copy the ship several times.

A scrapship follows the same approach, but is slightly more methodical: You begin with some minimal design that can be stored. Then you attach habitat and link modules to each side, which are then decorated with as many different pieces as you like. Alternating links and habs help to create more side walls, which you can use to attach even more pieces in a relatively compact shape. The example scraphsip on the screenshot below is close to the 100 piece limit, and contains almost all types of pieces, except for a few link types.
Be mindful about multiplayer with larger scrapships. Especially when you build one with many habitat modules, be sure to disable multiplayer in the network tab of the game options. Corvettes with many habitats can cause severe performance issues for others in multiplayer.

At the anomaly's expedition terminal, you can copy over a ship for just 2'800 nanites. Even if this amount may increase with future updates, it is an incredibly convenient way to stock up on tech and corvette pieces.
Once we have a copy of our scrap ship, we head back to the space station and uninstall all components except for the core design. Since we did not clutter the core with decorations, it is quick and easy to identify and remove all optional pieces. If free slots in the exosuit inventory are limited, the pieces are detached and moved to the vault in two or more steps. Finally, we look for visiting pilots and trade the core of our scrapship in exchange for a spaceship. Unlike the corvette, the spaceship can be scrapped at the nearby ship terminal. Thus we can repeat the process as many times as we wish without running out of slots in our ship collection.

Of course, you can alter the design of your scrapship to transfer different types of corvette pieces. Got enough of those wings? Maybe trade them for a few hull links to complete your collection. You are free to collect more pieces and copy as many variants of scrapships as you like. A few copies of one or two designs should give you more pieces than you will ever need, though.

Once you are happy with your collection (or bored with the scrapships), it is time to end the expedition. Just remember: Once the expedition is closed, you can still copy your last ship, but you can't get back to modify the scrapship.

I hope the information presented is useful to some fellow explorers.
Cheers and happy ship building!