Advice for travelling alone to Europe

I have been travelling alone to Europe and also South Africa for the past year. I discover few things which are vital and mostly common sense to 'guard' myself.

1. wear sunglasses to avoid direct eye contact

2. wear a ring (preferably not so fanciful ones) on the left hand - pretend that you are married to give a big no-no sign

3. always walk confidently

4. don't smile so easily to strangers - I was followed when I did this in Morocco

5.mini umbrella. Good against rain/sun/bash people up if needed :)