You can feel your Adam's Apple, for guys. Once you have established the frog, see where your Adam's Apple is. Then move it up a bit, like the Tuvans do, starting with a slightly forced "hur." What's happening is that you have the false or ventricular vocal folds above the vocal chords. The Tuvans tap into both of those. Once you get the frog you can begin to expand it. The Tuvans use slightly more tension in the back. The forced "hur" sound helps lead you into some harmonics. With the right adjustment and the right opening you can get just the right tone. So that's basically it. Just get a solid frog and use the Tuvan "hur" technique to launch into the harmonics.