How do you choose the license for your open source project?

If you can't be bothered enforcing the license, choose CC0.

If you can be bothered enforcing the license in a principled way, choose AGPLv3+.

If you're running a business selling the project, just go with proprietary instead.

You start by looking at the license of your likely dependencies. Some of them may constraint your options. For example if you have a non replaceable dependency under GPL.