Last night, I also wrote a short step-by-step guide before I decided to ask whether you wanted help on sprites or adding the ship. I'll post it here just in case you prefer text. And so I don't cry on wasted time.
((I wish this forum had spoilers, it would be easier for me to avoid cluttering up the thread))
First, I'd suggest making a mod directory with all the necessary folders. Including the Data/Hull, data/variants, and graphics/ships directories. I will be doing this step-by-step guide as if making a new mod since that's MUCH cleaner compared to just adding onto the core game.
After that:
Create the sprite;
Use a ship editor, like
this one to get the rough idea of the ship and create a hull, if needed create a Variant;
Put the hull in the Data/hull directory, and the variant in the data/variants directory;
Manually edit the hull file with a text editor to point to the sprite, manually edit the variant to put weapons in slots since the editor I linked to doesn't seem to work with assigning weapons;
Copy a ship_data.csv from either the core game files or another mod and fill out the ship's stats, id, name... Fill in everything (except "8/6/5/4%", that's unused);
Put the ship_data file with the hull.
Now, you have a choice. The ship will work now, but it's not actually being used by the game. You have the choice of making an entirely new faction or just editing the ship to an existing one. If you chose the former, follow ALL the instructions on
this and add your ships on step 1. If you chose the latter, copy the file mentioned in step 1 from the core game files and put it in a similar folder in your mod from where you find it. Then edit your ships into it. Note that any other mods that modify the faction will conflict if you just modify an existing faction.
Next, grab a "mod_info.json" from a mod and put it in the top directory of your mod. Edit it with a text editor to your liking.
Finally, you can start up the starfarer launcher, and select your mods. Select yours, then launch the game.
If you have devmode on, you can then edit your variants to see how off everything is with your ship right on the start screen and see if you messed up. Otherwise, you'll have to go fighting with or against your ship to see any mistakes. If you find any, I suggest messing around with steps 2 and 4 until your ship looks fine.
