Not currently healing as I found bard more fun after pre-season, but as a DPS, I'd say don't be afraid to remind people at the beginning, middle and even the end of the game to watch out for the healer. Even though I play as a bard and use WP sometimes i need a reminder as I can get tunnel visioned. I see a lot of good healers with macros they use before the game starts with simple tips/reminders, "Run back to base if the healer dies," "You can use purified on a slept teammate (healer)," etc. If you are new, you are probably playing with other new people who may not even realize they should help purify the healer.