The Midwest restraint works well for small to medium sized planes. Just be
aware that it can reduce the effective range if you use it to hold the plane
while range checking. Has something to do with its tuning fork shapeand
steel construction.

For larger planes use a loop of nylon strap threaded through
a piece of foam pipe insulation (to protect the plane...) and tie it securely
to a fixed obect, eg, a fence. Loop the foam protected strap over the
turtle deck and back under the stabs. You can buy the nylon straps of adequate
length at camping supply outlets.