Originally Posted by
The_Snark
I feel I should mention the Augment Elemental feat, found in... Magic of Eberron, I think? Unlike the Rashemi summoning feat, though, it isn't tied to any region or organization, so unless your DM prohibits all material from setting-specific books there's no reason it couldn't be used elsewhere.
It gives all elementals conjured with summon spells a +2 enhancement bonus to attack and damage rolls, and temporary hit points equal to twice their HD. In other words, it's almost identical to Augment Summoning, but it a) can stack with Augment Summoning, b) only affects elementals, and c) doesn't require Spell Focus (conjuration).