I'm not THAT experienced with recruiting but as no one has replied to you I will run some ideas by you for consideration - maybe that will spark a discussion.
You can talk about teaching all day but really the proof is in the pudding.
Therefore as part of the interview I would have the candidate actually teach something to some willing participants. Warn the candidate about this so that he or she may prepare for it. Then observe the teacher - you'll soon know if the candidate knows what he or she is doing.
If it is not practical to have students participating then be the student yourself and have the candidate teach you something or do part of a demo lesson on a particular grammatical point or topic.
Then you also want to find out where the teacher has taught before and get references.
All the best
For free games and activities to use with teens and adults - mostly targeting higher levels.