Fragging

Bone shears and superglue gel. 

Read a good book like Anthony calfo's coral propagation book. There are many fragging techniques and there are many ways of attaching coral to plugs. You just gotta find it in a reference somewhere or even attend a seminar. 

Basically, your asking a general question, asking for a coral specific response. 

I always liked this list as some general rules for coral propagation.

1. Never cut a coral if you believe it is not doing well, even if it is fully expanded and shows the species-specific growth form and growth rate. A suffering coral that has bacterial infections or is being held under bad conditions, such as the wrong lighting, high nitrate/phosphate values or unnatural pH/salinity values, should not be cut because it will very likely not be able to fight off attacking microorganisms.

2. Soft corals should only be cut using a scalpel or razor blade. Never use scissors because the shearing effect may “squeeze” the tissue and cause it to bruise, which can quickly become infested with microorganisms.

3. If you produce more than a few fragments, limit yourself to only one species, because the mother corals and the fragments of many species tend to set free large amounts of secretions when their tissue is being cut. Those secretions will partly be distributed in the tank system and can affect the condition of other corals.

4. If you stock the coral fragments in a bowl or bucket for a while before doing the substrate attachment (because you are still busy creating fragments), make sure the amount of water given to the fragments is sufficient and the temperature remains stable.

5. If the coral fragments belong to a species that produces plenty of mucus secretions when the tissue is cut, you might have to change the water in the bowl or bucket where you store the fragments. If the concentration of the secretions gets too high, the coral fragments might suffer.

6. Never keep fragments of different species or genera in the same bowl or bucket. Even though it is just for a short period of time, the secretions released to the water can severely damage each other.

7. When fragments have been set on the substrate, as much as possible they should not be placed in different environmental conditions with different water values. Though all the corals have a certain ability to adapt to different environmental conditions, the cut coral fragments are severely injured and might be unable to survive under different conditions.

8. Place the coral fragments under the same spectral light composition and light intensity as the mother coral has been living under. Up to a certain limit the corals can adapt to changes in illumination, but the separation from the main coral has a drastic impact on the coral and the healing process of the tissue, as well as its ability to defend against attacks of microorganisms. It could be fatal if at the same time it has to adjust to different lighting conditions.

9. If possible, place the fragments with only the same species in a separate tank. This provides the best conditions and the highest survival rates, especially if the mother coral has also been held under those conditions.

10. Many soft corals tend to develop tissue damage if the newly cut tissue is placed on a substrate without having healed first. It is advisable to keep the fragments unattached in the aquarium for about one or two weeks until the cut tissue has been regenerated and the wound is healed. Provide good lighting and a current that is strong enough to supply oxygen, but does not blow away and relocate the fragments. Some coral species (e.g. Nephthea species) will even try to lift up the cut tissue into the water current, probably to improve the healing process by enhancing the oxygen supply.

Also  go to the first link here. A good list of articles and tutorials.

http://www.google.com/search?q=Articles+or+Online+Tutorials+on+Propagation&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a