I have a fairly robust CRM system that allows me to easily and effectively track when I contact a client. It also has some automated emails that can be sent depending on the type of contact and holidays (have they already purchased a home, are they going to be purchasing/selling a home soon, home anniversaries, birthdays, etc.)  I also will use time blocking to ensure I have time on my calendar for coffees, appointments, etc. All appoinments, coffees, etc go onto my digital calendar. I receive reminders on my phone.