How can a researcher in his early career attract good PhD students?
Presuming you have some way to fund their work, and you have positions to offer, I suggest you start by recruiting bright undergrads from your upper-division courses. Get them involved in your research before they graduate. Offer them positions as PhD students before they apply everywhere else*. I was so excited by my PhD supervisor's work (our work really), the lab environment, and the place where I was living, that I didn't want to apply anywhere but where I already was. 

Some people will object that students should move around between their undergrad and PhD, and there's some merit to these arguments, but if you have funding and can't recruit, you may want to think outside the box a bit. If you don't have any money, or your department won't give you any positions (or whatever the system is at your university), get some!

If you want to recruit from outside, keep publishing. Publish in the best places you can. Become a hot shot. Advertise openings on your website and at the end of your conference talks (if that's acceptable in your field). Be aggressive about finding good students. 

*: If they do want to apply elsewhere, write them the best letter you can and wish them well. Maybe they'll stay anyway. Don't be one of those profs with a reputation for trying to control the lives of your students by refusing to write recommendation letters!