I just created a Void Elf Priest and have some issues. From what I understand, I use the Atonement buff on the tank, do damage and he should heal and refresh Power Word Shield and use direct healing when necessary.
Practically speaking it seems more difficult. I have a hard time targeting enemies and keeping an eye on the tank and easily switching back and forth. I can heal fine if I just focus on the healing.
Are there any good add ons or tips to easily handle this.
other than mouse over macros so you don’t have to switch off mobs to heal, the only thing that’ll really help is just experience.
Hmm well first make sure you configure your party frames as Raid frames, there are Raid Frame addons but you should be fine with the standard UI, just need to make sure to enable the option to use Raid style party frames, they are easy to customize to make them look a bit nicer too.
The other thing is mouseover macros or you can use an addon like Clique. The goal is that you don’t need to target the friendly player to cast your heals, just hover your mouse over his name in the raid frames and have the heal cast on your mousever rather than your target, that way you can keep targeting enemies while going back and forth from healing and DPSing.
Get Grid2 or Elvui. Tab target so that you can keep your eyes on your bars, put your bars a little below the middle of the screen so your eyes don’t have to move very far.
Besides the addons listed below you can set focus either on the boss or tank (if fighting mobs keep tank)
That way you know when to reapply atonement or if you need to use pain suppression or smth else to help the tank.
Move your target/focus and player frames close to your character so you have everything within view.
Another useful thing is to keep your raid frames of member right underneath your character that way again you see everything without having to look for stuff.
You can modify your buffs in addons to appear larger so you can see atonement better as well.
As mentioned mouseover macros help a lot. One minor thing that has helped me is knowing that smite will auto target enemies, so even if you have to target someone to heal them you can just hit smite directly after to quickly start dpsing again.
Just use tab to target nearest enemy and make a keybind to target party member 1 I use scroll down on my mouse
Tab targeting is a good way to pull the wrong mob in a different pack 
Tab targeting is fine, just need a little awareness to make sure you don’t accidentally pull stuff, it’s really not difficult to manage and I much rather have control of who I cast my spells on than having them cast on whoever the tank is targeting.
Plus having enemies as my target allows me to better watch what they are casting, who they target, or buffs/debuffs they might get.
Download the addon vuhdo. It might seem difficult to configure but it’s rather easy and its awesome. One of the most healing addons used by top players due to its highly customizable features and effectiveness.
Check this guide to quickly configure it https://youtu.be/UaEk3l0YYtU
Elvui is a fantastic ui. I love it for disc healing, second is vuhdo. I use these profiles and can move them to where I need and can mouse over and left click(my preference) and cast pws and right click a portrait for shadow mend. Then move my mouse off of them and it’s back to normal left and right click function. Super helpful. I also have an attonement watch but since vuhdo can track my attonement in a simple easy way i don’t use it as much unless raiding.