Oldranger,

Using a signal mirror takes some practice. For instance, what do you do when the sun is behind you?

The only bright surface I might have with me is a beer can cut and flattened so I could use the inside.

Then I'd put the reflection on my hand and then rotate it so the reflection was pointed towards the helicopter and take my hand off.

If the inside of your sleeping bag is a light color, you could turn it inside out and wave it.

If there is time while you are waiting, it might help to lay all your gear in a straight line. A smokey fire could help, too. Keep a good fire going and then cover it with leaves when you need the smoke.

Good point about being by a letter.