At a basic level call NFT art generators work in much the same way, with you uploading your art and layers and the app creating up to 10,000 variants without you needing to code. Below is a basic structure:
1. Create your art in Photoshop or a similar digital art software, including all your layers for the NFTs various traits (i.e. sunglasses, clothes, expressions, etc).
2. Upload the entire folder to the NFT generator, or each layer one at a time depending on the platform you're using.
3. Once in the generator you should be able to live preview the NFT collection and the best ones will enable you to shuffle the layers around.
4. Once set you can generate the collection and export your NFTs, either as a zipped folder or register to a blockchain, again, depending on the platform.
5. Some platforms will offer web page creation to launch and mint your NFT collection, they will enable you to set smart contracts and even set the collection for inclusion in a metaverse.