While it sounds like you may be crafting new Pokémon in Pokémon Scarlet & Violet, Pokémon crafting materials are actually used for crafting TMs. It's a new mechanic introduced in Generation IX that seems well-received by fans who are relieved they can grind to gain extra copies of their favorite moves. Here's how to farm Pokémon crafting materials efficiently in Pokémon Scarlet & Violet.
How to get Pokémon crafting materials quickly in Pokémon Scarlet & Violet
The easiest way to build up your stockpile of Pokémon crafting materials is to use the new Let's Go feature. While Let's Go mode significantly decreases the amount of EXP your party gains per battle, it increases the odds of receiving Pokémon crafting materials after a battle and helps you knock out battles quickly. The only reason you would not want to use Let's Go mode is if you wanted to farm for EXP simultaneously.
One important note: Evolved versions of a Pokémon do not have their own unique crafting materials. Defeating a Persian will give you Meowth Fur, same as defeating a Meowth would. In fact, it will generally give you double the material drops that defeating the pre-evolved Pokémon would.
Looking for info on some of the newer Pokémon in Pokémon Scarlet & Violet? Check out Where to get Toedscruel in Pokémon Scarlet & Violet and Best Nature for Tandemaus and Maushold in Pokémon Scarlet & Violet here at Pro Game Guides.