Invest in your actual network. It makes ignoring recruiters extremely easy. I try to remind myself of this.

Also, keep a curated list of headhunters that you respect.

I once was talking to a headhunter about a position he had (IIRC). I wasn't interested, but mentioned someone else he should look at. When he found out where my contact was currently working, he said, "Oh, they're a client. I can't recruit from there."

He went on my list. A headhunter with ethics about not stealing employees from his own customers? That's good enough to make him someone I want to talk to when I'm in the market.

Keep adding to the list on the (rare) occasion that a headhunter does something that catches your notice. Takes five minutes a year, if you're lucky. When you're next looking for a job, it can save you days.