How not to lock your keys in the car

Today I had to drive a spare set of keys to someone I know who locked her keys in her car.  I have not locked my keys in my car in years.  In fact, I may have never made this mistake.  Here are a few thoughts on how to avoid this error.

1.  Begin a habit of always checking your person for your keys before you lock the doors.  Feel the keys in your pocket, touch them, and sense their weight.
2.  Use the fob.  By using the electronic locking mechanism on your keychain, you know you already have the keys in your possession.
3.  Don't allow yourself to be distracted.  Let others do what they may, but you are the driver so you need to have the keys on you before you lock the doors.
4.  Feel the pain.  Your time is important to you and it is limited.  While waiting for someone else to show up to rescue you, think about how this is a terrible waste of your time.
5.  Pay the money.  A quick search for locksmith's shows that a lock-out service call starts at $35.  Go ahead and call, pay the money, and think about how you could have spent this money so much better elsewhere.  This pain point will create a hesitation every time you leave your vehicle causing you to check that you have your keys on you.
6.  Have an extra set made.  This idea is less practical today as keys have computer chips in them that drive their costs way up.  In the old days, people could get an extra key made fairly simply and then they would get a magnetic key holder and place it under the back bumper.
7.  Keep your car clean and empty.  By clearing out the junk and the valuables, you will not have anything in your car that is worth steeling.  That gives you the option of leaving your car unlocked.  Of course, you don't want to walk away from your car with the keys in the ignition because the car itself is valuable.