I avoid giving a number early on in conversations. Rather than naming a number, I like to 'seed' the conversation with talk about market rate, 'premium' on top of that, and similar phrases to move them in the right direction.

Establishing a position of strength can also mean other things like having the company and hiring manager invest as much time as they can in recruiting you; not hiring would be worse to them than over paying a little.

Also, having other offers on the table always helps negotiating better. Even if its never mentioned to the recruiter I just happen to negotiate better with the mindset that I have other options.