If you are an iPhone user, like me, then the very least you should do is the following:
Passcode Lock > Enter a 4 digit passcode, different from your bank cards PIN code
If you want to be slightly more secure also do the following:
Auto-Lock > 1 Minute
And that’s it. Those are the basic steps to secure your iPhone. Oh it can get more complex and thorough than this but really everyone can follow the above instructions.