View attachment 288720
Application Name: Name of the game you want displayed.
Author Name: You or whoever/whatever you want here
Title ID: Hit the random key to generate an ID
Icon Path: Where you have the icon you want used when you select the game.
Logo Path: Small logo you see when you boot the game. On the upper left corner will be your logo and the standard switch animation on the bottom right. You can customize the upper left logo as long as you are within the parameters.
Disable Image Conversion: I keep this checked because I keep my images saved to the parameters of the application (256x256 for icons, 160x40 for logos). I have heard that enabling the image conversion results in more artifacts in the image but I can be wrong. However, if you're having images show up as "?", try this checked on.
Custom prod.keys location: I like keeping the prod.keys in the root folder of the app.
Forwarder Options: Check the Retroarch Rom Forwarder for this usage.
Core Path: This is the path on your sd card from the root to the core you want to use for the rom. In this case, I am pointing the forwarder to use fbneo_libretro_libnx.nro, which is the Final Burn Neo core.
Rom Path: This is the location of your rom you want to use with the core you selected in the previous step. In this example, my roms folder is in the root of my sd card and I point the forwarder to find the specific rom I want. In this case, it's X-Men Vs Street Fighter.
Create the Forwarder and install as normal.
View attachment 288721
Best of luck!
Edit: As for core configurations in retroarch, I use per-core overrides or per-game overrides as needed.