In the week 5 of Plutus Pioneer Program Lars described how to make NFT by spending an UTxO while minting, therefore ensuring the uniqueness of the token.
Are there any other ways of making NFTs unique?
What if I wanted to create let's say, a collection of thousands of unique tokens. Creating as many UTxOs to refer to them further on would incur significant cost in the fees. Are there any cheaper/simpler ways to do it?
PS: Solutions not available in Plutus yet are also welcome as examples.