oral practice so if the language you are introducing is used in the written form then give a written drill! drills can become a bit boring & predictable if you don't keep them snappy & lively so make them fun, & with individual drilling dot around the room to keep everyone on their toes.
it's also not the case that higher, more advanced levels don't need drilling. if they find something difficult to say then drill them. clearly they are going to find less language that is difficult to say than lower levels but all the same if it's difficult to say then help them out. 