Substitute pitot tube cover:

Brightly coloured squeaky dog toy. Once your dog chews a hole in it and the
squeaker won't work unless you hold your finger over it to confuse your poor
puppy, then you can use it knowing that it will be visible and remembered
during preflight.

Now I will have to find a substitute source for those incredibly useful
little plastic containers!)

Drop into your local photo lab when you are shopping and ask. Most will have
a bucket full they haven't taken out to the industrial bin that day and are
happy to have them go to a good home. It also saves the shop assistant a
trip out to the bin!

Peter