In case anyone is having trouble with heel-toe, there's another doubles technique that I've been trying out, it's really intense. It's played heel up, but you go for a double stroke with each foot just like heel-toe. The motion is similar to heel-toe, except you initiate the stroke with the part of your foot just beneath your toes and then use your toes for the second stroke.
Like heel-toe, it is less tiring than playing single strokes, since you use less stamina to execute every pair of hits.
It's not an "established" technique and I am still working on it. I find it has advantages in being able to play at slower tempos as well as faster tempos, whereas conventional heel-toe is better put to use at higher tempos due to the exaggerated motion you have to make at slower tempos when it would be better to just play full length strokes, imo. I used to play heel-toe, but was never able to eliminate that galloping sound you get when you're not doing it right.
Here's a video that I did on my Roland TD30 to demonstrate the technique, hopefully someone will find it of use. I even lay into some triples with the technique in the video.
[youtube]https://www.youtube.com/watch?v=H_9r5VH0N1c[/youtube]
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