Print with at least 5 perimeters and 50% infill (Gyroid) in PETG or PLA+ for a strong print. Attach with M4 screws and appropriate hardware. I designed these with the proposed standard by Offset Skate Supply (Link and technical PDF below). If you don't have hardware there are lots of kits online for cheap. I designed a version of these a while ago for my Uncle and then redesigned it from scratch in different sizes to have more options and be more reliable. Enjoy and happy skating!
Note: There are slight changes between the model and the photos. The render is more accurate to the models. I added the photos anyway to give an idea of what it looks like in real life. Photos show the 8-inch model.
https://offsetskatesupply.co.uk/product-category/accessories/skid-plates/
Helpful video:
The author marked this model as their own original creation.