1. Don't turn off the reminder emails from your registrar. I know they can be annoying and you probably get too many of them, but turning them off means that you won't know when your credit card expires and your domain isn't going to renew automatically (for example).
2. Use a valid, real email address for your owner contact. Use WHOIS Privacy if you are concerned about spammers harvesting WHOIS for emails. Don't use support@ or webmaster@ unless you check those emails regularly. ICANN now requires your registrar to verify your email address and a single bounced email to the owner contact triggers that process. If you don't see it, you'll be offline in 15 days.
3. Treat your domains as the valuable assets they are. Yes, $15/year...not expensive in the grand scheme of things. But the value of that domain is likely much, much higher to you and your company.
ps. More on the new ICAAN registrant verification process which started on January 1, 2014 can be found here: https://help.hover.com/entries/25406514-Registrant-verificat...