Here's some pictures of my door safety strap. It's simply a nylon strap
with "industrial strength" velcro. Velcro loop portion on handle. Hook
portion on strap. Strap is riveted under the door striker plate. No mods
to aircraft. No extra holes. Cost less than $10 (Home Depot). Provides
visual confirmation that door is shut and is virtually impossible to open
when attached. Also prevents stuff from snagging under the door handle. In
an emergency, strap can be removed from outside through door vent. All in
all, I think it is a good solution. I flew with it today and it worked
perfectly. Strap is folded over twice at end to provide a pull tab. Folds
are glued together and then edges melted to hold it. Velcro glues on. Used
a hot nail to melt three holes for the rivets. That's all. FYI

--Angus