How can I keep my personal phone number private when signing up for new accounts?

I'm tired of giving out my personal phone number every time I register for something new. While I understand that some services require it, it often feels excessive and results in a flood of spam texts. I'm looking for straightforward and easy solutions that don't require any technical skills. How do others manage to protect their main phone number? Do you use a different number, or have other methods for keeping your real one safe?