Watch the Math Rock Shuffle One online guitar lesson by Angus Clark from Hard Rock Survival Guide: Rhythm

Sometimes you have to count to make it through a complicated or non-intuitive rhythm part. I try to avoid that as often as possible. We start with a kind of Sabbath shuffle, followed by a triplet riff that expresses the underlying 6/8 from the shuffle section (trip-e-let trip-e-let, etc.). Then we add 2 notes into that riff so that the time signature changes (trip-e-let-and-a-trip-e-let) to 8/8 (or 4/4 if you're really into math). But the point here is just to learn the riff and not worry about counting it. It's like learning "Black Dog", you just learn one note after the other until you know the whole riff. This is indicative of a lot of hard rock material that maneuvers through time signature changes.