It depends on how my team is set up. If I'm playing a team where multiple characters have heals, I'll usually use repeaters and clicks. If only one character is healing, I use macros.

For my "multiple healer" teams basically I don't have a dedicated healer - I just have the click region for each character, and when a character is being hurt I left click (my single-target heals are bound to that), whoever is available to cast will cast a heal, and so on. If it's AoE damage, I right click (this has everyone use their AoE heal or multiple-target heal) and it's good to go.

For my single-healer setup, I usually just have 2 macros: tank heal and then aoe heal.

Right now I'm rolling in a group that has a ton of passive healing (Word of Glory, Healing Stream totems, Earth Shield and Smite healing) and it's pretty amazing.