After cutting it, you can also, stick a toothpick in a hole in the rock, and push the coral onto the toothpick. This will hold the coral in place until it attaches itself.
I find softies to be difficult to glue, so toothpicks or loose fitting rubberbands are better to use.
If you use a rubberband, keep it loose so as not to crush the coral, just enough to hold it in place. If it is too tight, the piece under the rubberband will die.