Your build is important in determining how much you should worry about concentration. In general If you wade into melee regularly, you either need to limit your concentration spells or do something to increase the probability of passing. Warcaster is the most common solution, since advantage will help you hit the DC: 10 much more frequently. If you're a ranged caster, concentration shouldn't be as much of an issue, since overall you'll be hit less. Another option is to pick your concentration spells to either help (Bless including yourself) or assume you'll lose it after 1-2 rounds. Hold Person and other spells that grant a save each round are good examples, because it's unlikely you'll have them up for long anyway.
My current cleric is a focused on casting Spirit Guardians, so I aggro a LOT. To prepare for this, I have an 18 Con with Resilience, which allows me to to only fail on a roll of a 1 (for 20 damage or less), and if our paladin is close I can't fail unless the damage is well above 20. I take a lot of damage in the process, even with AC 20, so I'm much more likely to lose concentration due to going unconscious.
My current cleric is a focused on casting Spirit Guardians, so I aggro a LOT. To prepare for this, I have an 18 Con with Resilience, which allows me to to only fail on a roll of a 1 (for 20 damage or less), and if our paladin is close I can't fail unless the damage is well above 20. I take a lot of damage in the process, even with AC 20, so I'm much more likely to lose concentration due to going unconscious.
