Try not to spilt domains across registrars and accounts
Having your domains registered with multiple registrars makes it harder to manage your portfolio. Keep all your domains with ideally one registrar and you will save yourself a lot of time in administration and reduce the risk of accidental dropping a domain due to missed payment or renewal.
Keep your contact details up-to-date
Registrars are usually pretty good at keeping their customers informed about information regarding their hosted domains. If your contact details are up-to-date you reduce the risk of missing a renewal email and losing a domain.
Be aware of price increases
Domain registrars have a sneaky habit of increasing domain fees every year. Namecheap for example of a cheap initial registration price, but then the renewal price is a lot more. Watch out for price increases as this can seriously increase your costs if you have a large domain portfolio.
Have several payment sources registered
I always like to keep a couple of cards registered with my domain provider. That way if a card expires or fails to process for whatever reason there is always a back-up card the registrar can automatically use to renew a domain. The last thing you ant is for a domain to drop because your card has expired and payment fails. Never miss a payment by keeping your payment details up-to-date.
Don’t be scared to move your portfolio
Moving your domains to a new registrar can be a hassle, but it is certainly not the most complicated thing in the world. Don’t stick with the same domain registrar if they have bad customer support or keep increasing prices. Vote with your IPS tag and move on.