This is a fun move I named after one of Sargent Major Avery's last quotes.I found this out in ODST and I haven't tried it in reach yet but here's how you do it.

step1.Take out a sheilded enemies' shield with either a charge plasma bolt or just by simply punching him until his shields are out.

step2.If its a brute,He will usualy be stunned after having his shield taken out.This allows you to stick him with either a brute spike grenade,or a common plasma grenade.

Step3.Once the grenade is applied,melee him and he will usualy fall back a good distance enough for you to not be effected by the explosion.
TIPS
.If the elite/brute is leading a squad, use this to your advantage and try to get the explosion just in the center of the pack.
.This can also be a last resort of cornered in a small cramped space during combat since dead bodies go right through alive ones anyways.
.This "move" will also look good in machinima.
.You can actualy use it on anyone,just make sure you can kill them just by meleeing first.

Have fun