Good article to get you bullet-proof against ID theft. 

10 simple steps to follow. 

Two in particular caught my eye. 

#2 refers to tiny 1 pixel images that are embedded in emails. These tiny images reveal your location, the fact you opened the email, and that your email is valid. All gold-dust to a hacker. 

I had no idea about these nasty images. If you are on iOS you can block them. Not so if you use Gmail however. Bit of an own goal by Google but there we go. 

Also, have a look at #6 which focuses on free wi-fi spots. Worth a read.