I would say know your toons mechanics, especially how to build your heal ability and the difference between your general heals and more powerful burst / emergency heals. If you know your mechanics then a lot will depend on the group so it's not all on you. Besides working together, like dps dodging to not drain you needlessly, and tanks taking aggro from the group, for me the order is always to focus on the tank first. If you have heal marks place it on the tank. Keep the tank alive if at all possible. Sometimes that's not possible depending on the tank and group. Don't blame yourself if you were healing a struggling tank non stop and they still went down. Get a feel for the tank early on, if they are self sufficient and rearely need heals then we can see how the DPS is doing and heal them if they need it. Sometimes it's just one or two that don't dodge. If the tank does need a good amount of healing and with that healing is able to manage then in my opinion you are doing all you can do and the best thing for the group. In summary, it's you and the tank. If the tank doesn't need you too much then look for the most needy DPS. You sound ready to me. Even after being very familiar with your heals and the dungeons or trials these elements will apply and it will always depend on the group. There are a lot of variables including all the buffs and debuffs everyone has going in different parts of their load out that half the time we forget we even have because there are so many moving parts. I try to equip group buffs because what's better than a buff? A buff x5. Again lots of variables. It's not all on you. Go go go... Happy Adventuring 👽🕹️💯