A nice elbow combination for Muay Thai. Might be hard to write out, but here goes.
While pummeling or in close distance:
Throw a lead cross elbow.
Then with the arm you elbow'd with, make some room for you to throw a downward elbow.
Make sure you swim your elbow back down and your hand up, grab the back of the neck (thumb down) and scoop the head towards your other arm throwing one more elbow that crosses your body to his head.
You actually leave your hands in a perfect spot for a clinch if you didn't level him with the elbows already.
Note, you could also scoop his head in the other direction and throw an upward elbow across the body right under his chin.
Nice little 3 elbow combo that we were working on in class a few weeks ago that I have been able to use while clinch and elbow sparring. If you are fast, it works well.