Anything goes if it improves driving safety, helps in awkward situations, etc...

Here's a couple of mine for starters:

-Stopping on the motorway hard shoulder, turn your wheels towards the grass bank. If someone runs into you, your car won't run across three lanes of motorway

-Parallel parking - Look for a reflection of your car in shop windows, you might just be able to gain a few inches without fear of bumping into someone else.