One generally crimps the spade connectors using a crimping tool. Your connectors and crimping tool need to be of compatible types. Use of smaller wire gauge requires more drops to share the current load. I find 18 gauge is a good balance.
You can see in this post a common style crimping tool:
https://ogrforum.ogaugerr.com/...48#43383979845806748
I personally like the Klein Ratcheting Crimp Tool for the standard vinyl crimp connectors::
https://www.amazon.com/Klein-T...-10-22/dp/B07WMB61J5
The jaws are changeable (sold separately) for other terminal types: