[Mark is right,, this is the way I do all my frags as well,, and if you are doing sps frags you will notice that out of water SPS corals have a Gel/slime coat over them. In the wild some of these are exposed to direct sunlight when the tides change for hours at a time. Its a defense for them . So with hard corals its okay to hold the frag in place while gentley blowing at the base to get it to set..
Generally with softcorals their is several ways to get them to attach. one of the easiest is to take cheesecloth , place your fragment on what is going to be its home and wrap the cheese cloth around it with a rubber band on each side. wait 2 days and then remove it. Another way is to take fishing line on a needle and pierce the coral and tie it down. after 2-3 days cut it off ,, it will attach.......]