When adding a crash at the start of a bar with hi hats on offbeat eighth notes they will still fall on the numbered count. That would give you something like this:
Or this with open hi hats:
You could also skip for the first hi hat to give the pattern some space, that would look like this:
Adding crashes on the snares can make a nice fill variation also. There are some examples of this below.
- Learn the patterns above to a tempo of at least 120bpm.
- Try different kick and snare combinations.
- Use the groove as part of a longer phrase both as a groove and fill.
To further clarify this concept and to provide a practical example a short piece has been given below: