Some are very basic but it is good to read it every now and then as a reminder to keep myself on track.   

If they’re not ready, remind them to think of me.

I would extend the close to whatever date makes the seller feels less guilty - but I would remind him that he is running a business and selling the property is a business decision.

You might want to burst their bubble and remind them that values decline, as well. 

Politely and professioanlly remind her who is "boss".

@Kim Hopkins, remind me again what the name of your firm is (if you don't mind sharing)? 

They paid on time except for one time we let him pay 4000 for 3 months because he was trying to qualify for an SBA loan which he wanted to do verbally (gee I wonder why) He made of the difference a few months later which we had to REMIND him about. 

Remind yourself what you do for a living and let a pro handle it for you.  

You could remind tenant to provide you with their forwarding address.

Plus text messages as a reminder through out two years.