Quick rundown:
1) Cast BoH
2) Hit at least two enemies with the second strike of WotHF (if your spirit instantly fills you should be good)
3) Blind
4) Overawe
5) Bells
6) Refresh Overawe if stuff is still alive.
Main key to the build is keeping spirit regen: Do NOT kill the target(s) that you tagged with WotHF. That "DoT" from WotHF is what powers your spirit regen. If those targets die your spirit regen dies, and if you're running zero LS then no spirit = no sustain = GTFO or die.
What I'll usually do after tagging my (trash mob) WotHF targets is dash to the other side of the pack and drop bells from there, where they won't hit my original target. Once the big pack is dead you're free to dash back and kill off your first targets. Chargers, plague nests and trees make good WotHF targets too due to their large HP pool.
Vs elites/champs it's a different setup as you can WotHF on them, but then unload all your bells on them too since they have a ton of HP and aren't likely to die too fast (unless running a lower MP of course)
Note that you do need at least two targets for unlimited spirit regen - one won't do it, so if you're down to one elite left tryto kite it to other enemies.
Dropping goblins in 2-3 seconds on MP10 never gets old
*EDIT*
Just recorded a vid of a FoM run on MP8. Originally did MP10 but after two extra health RD packs in a row said "hell with that" and dropped down to MP8. Encoding tonight so will link when it's done