Memories

Take lots of pictures.  Then, from time to time, sit down with your kid(s) and review the photos of some event or trip.  It'll help keep their memories alive, including associated details that aren't necessarily in the pictures themselves.  Thanks to this practice, I believe, my kids remember more things, and from earlier ages, than I previously thought possible.

Keep a napkin handy

If you don't already, you should have some kind of wiping tool (hanky, paper towel, napkin) on your person at all times.

I kept a clean, dry napkin in my left front pants pocket from the time Amelia was born, until she was about six. Every time I was about to leave a restaurant, if there were unused paper napkins on the table, I checked my pocket to make sure I was stocked.

They all got used, every single one.

I still check my left front pocket occasionally.

It's a phase

Whatever parenting thing is driving you crazy right now: it's a phase and soon you won't even remember it.

Your favorite possessions

Reconcile yourself to the knowledge that your favorite possessions will be lost, destroyed, or made sticky.

Talk is cheap

At all costs, embody the behaviors you wish to see in your child.  This does not mean be perfect, but it does mean that when you screw up, you embody apologizing and making things right.