Teach the distress signals for survival skills badge.
The recognised mountain distress signals are based on groups of three, or six in the UK and the European Alps. A distress signal can be 3 fires or piles of rocks in a triangle, three blasts on a whistle, or three flashes of a light, in succession followed by a one minute pause and repeated until a response is received. Three blasts or flashes is the appropriate response.
In the Alps, the recommended way to signal distress is the Alpine distress signal: give six signals within a minute, then pause for a minute, repeating this until rescue arrives. A signal may be anything visual (waving clothes or lights, use of a signal mirror) or audible (shouts, whistles, etc.). The rescuers acknowledge with three signals per minute.
In practice either signal pattern is likely to be recognised in most popular mountainous areas as nearby climbing teams are likely to include Europeans or North Americans.
To communicate with a helicopter in sight, raise both arms (forming the letter Y) to indicate "Yes" or "I need help," or stretch one arm up and one down (imitating the letter N) for "No" or "I do not need help".
On camp, try making smoke signals as a competition - who can make the most smoke in the shortest amount of time.
Discuss some basic actions to take while waiting rescue that will both keep you (and your group) safe and will assist your rescuers in locating you.