Another common strategy is to use Dwayna's Sorrow on the minions for a partywide heal when they die.
5 points in Soul Reaping results in these minions being effectively free (5 energy from the original death, + 5x2 on minions' deaths = 15, the spell cost). Each additional point in Soul Reaping results in 3 energy gained each time you cast Animate Bone Minions (at Soul Reaping level 16 you gain 33 net energy every time you summon Bone Minions.)
The two minions count separately towards the Minion Master's maximum limit of minions (10 minions at 16 Death).
Animate Bone Minion's skill icon portrays them as looking similar to Scarabs, a type of enemy which can be found in several regions on Tyria, however, they actually have the appearance of smaller Bone Horrors.