We were also asked to teach "tugging" at our kennel club training class. The instructor seemed a little surprised when we told her that we don't do tugging with our (then 6 mos. old) pup. She asked how do you teach "drop it" then? It was kind of a mute point because he already knew "drop it" from going thru the "pick up anything off the street" stage as a younger pup. Having to retrieve an undesirable object from his mouth (such as a frog) a couple of times, did the trick. We primarily use "drop it" in these types of quick react circumstances and our boys learned the command easily.
As cbrand stated, we also use "give" the majority of the time, especially during fetch and retrieve sessions. We did not want our dogs to think that tugging when we put our hands on something he was holding,
was an option. We had the same concern regarding this type of play with children. We did also have to teach the children not to play this way with our spoos. Sometimes this is more challenging than teaching the dogs

.