Here is a fairly simple chord progression and common metal guitar strumming pattern. Although it may be simple and straightforward, getting this up to and beyond 180 BPM will prove to be quite challenging for most people. How fast can YOU get this?

The count for this rhythm is 1en_2en_3en_4en_

This was given to a student so they could work on gallop and reverse gallop rhythm, along with palm-mute accents.

All of the 16th notes are palm-muted. None of the 8th notes are palm-muted. Doing this makes the 8th notes stand out more.

The count for this is

1_na2_na3_na4_na
1_na2_na3_na4_na
1en_2en_3en_4en_
​1en_2en_3en_4en_

This was given to a student to help them work on metal rhythms that mix up down picked 8th notes and reverse gallop strumming.

The count for this is

1_n_2_3en_4en_
1_n_2_3en_4en_
1_n_2_3en_4en_
1_n_2en_3_n_4en_

This was given to a student so they could work on their palm-muting technique and reverse gallop strumming. 

The count for this rhythm is 1en_2en_3en_4en_