How small are the frags?
Remember they have just been snipped/fragged so after you place them in the veil, place them in a low light/flow area so it can recover.
I just fragged my Kenya tree, identical to Colt coral. All I did was tear a piece of the tree off (barbaric, yes I know - just like in the wild.) Then I took a needle and threaded it once through the center and tied it up to some rock rubble. Make sure its not too tight and place it at the bottom of the tank as opposed to the top where the mother colony is. Recently the mother colony dropped 2 babies and they attached by themselves and are open/growing very nicely at the bottom of my tank.