I haven't seen anyone mention that it helps to anchor the tip of your tongue at the base of your lower front teeth--right there at the gumline. This gives you a stable base for controlling tongue movements. With your tongue in that position, you have a choice of two locations for the focus of the bend.
The easiest way is probably the forward locus: Pretend you are humping your tongue forward to squeeze a marble or pea (smaller the higher the note is) against the back of your lower front teeth. Got that? Your tongue tip is anchored lightly at the gumline, you've got an imaginary pea sitting in the top of the tip, and you're humping your tongue forward to squeeze that pea against the teeth, redirecting the airstream so it feels almost like it's pointed downwards. This method comes from David Harp's instructional books. You should be able to bend the 9 and 10 blow on a G or A harp down all the way down and back up continuously or stop/start at the half-steps when you're doing this right.
The best way, in the long run, IMHO, is to focus the bend at the back of your mouth, back where you make the H sound. Anchor your tongue tip at the gumline as before, but try humping the back of your tongue, back in the H-sound area, to get the bend happening. The front of the tongue will still hump a little, but you can actually move the focus to the back, getting the same bend with a smaller movement and less spit transfer, and this enables you to do the high blow bends tongueblocked if you work at it (anchor your tongue very lightly on the harp & hump the back of your tongue).
We have this choice of two areas for the lower draw bends too (try it with 3Db), and again some people think it's better to focus on the back of the throat because it ultimately gives you better control and more freedom to do things with the rest of your mouth at the same time. In addition, smoother overbends come from the back of the throat, so focusing on that area helps tie everything together.
