Interface
This is a screenshot of my Balance Druid UI in combat:
You can download my UI pack on Wago for free at https://uipacks.wago.io/pack/gamz-ui.
If you prefer to make your own personal interface, which is always the best choice, there are some bare minimums you want to have as a Balance Druid:
A resource bar that is easy to track, either through standalone add-ons like Twintop’s Resource Bar or Sensei’s Class Resource Bar.
A way to easily track your buffs like Lunar Eclipse/Solar Eclipse and procs like Starweaver and Touch The Cosmos.
Personally I use the add-on Better Cooldown Manager which includes a cast bar, resource bar and options for custom tracking. You can see in the screenshot above that I have spells and items like trinkets, Barkskin and Healthstone anchored to my player frame.
Another notable add-on to have is BuffReminders, which simply alerts you if someone in your party or raid doesn't have the Mark Of The Wild buff active, reminding you to re-buff them. It will also remind you about using consumables before pulling a boss, like Flasks, Food and Weapon Oils.
Macros
Force of Nature Cursor
This macro lets you cast Force Of Nature at the position of your cursor.
#showtooltip
/cast [@cursor] Force of Nature
Celestial Alignment Cursor Macro
This macro allows you to cast your Celestial Alignment and have your Orbital Strike go to your cursor without having to do multiple clicks.
#showtooltip
/cast [@cursor] Celestial Alignment
Innervate Target Macro
This macro lets you cast Innervate on a specific target, so you don't need to manually target them or have to hover your mouse over the target to cast.
I would recommend using this and a mouseover macro. Replace Name with the healer's name.
/cast [@Name] innervate
Innervate Mouseover
This macro lets you cast Innervate on your mouseover target.
#showtooltip Innervate
/cast [@mouseover,exists] innervate
Sunfire/Moonfire Mouseover Macro
This macro allows you to cast Sunfire on a mouseover target without de-selecting your main target.
This is beneficial for when you need to apply your DoTs to alternate targets, but do not want to de-target a priority target. Furthermore, this mouseover will help apply dots using Boss Frames if you have an addon that allows for proper tracking of your dots on boss frames.
You can customize this to include Moonfire and Stellar Flare as well by simply changing where it says Sunfire to Moonfire or Stellar Flare.
#showtooltip Sunfire
/cast [@mouseover,harm,nodead][@target,harm,nodead]Sunfire
Remove Corruption Mouseover
This macro lets you cast Remove Corruption on your mouseover target. If the target character is dead it will cast Remove Corruption on your current target.
#showtooltip Remove Corruption
/cast [target=mouseover,help,nodead][target=target] Remove Corruption
Rebirth Mouseover
This macro lets you cast Rebirth on your mouseover target.
#showtooltip Rebirth
/cast [@mouseover,help]Rebirth;Rebirth