When a guest makes a reservation, I put his/her name immediately in my phone (after I have sent all information) in a special way.
Take a look...
AAA + first name guest + abbreviation of listing
The name of my listings start with AAA and in this way I see these contacts on top of my screen.
When a guest calls, I immediately respond with his/her first name and I see where and when they are staying.
Once per week I delete all guest names, which have left.
Just saying ;-)