Interface
In general there are a few must have addons for Balance Druids.
WeakAuras and Plater are two of the ones I recommend most, as they will allow for easier tracking of things like dots, eclipses, trinkets, etc.
Having ElvUI or Shadowed Unit Frames for your frames is a huge advantage as they have a lot more customizability compared to the default Blizzard frames.
Macros
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
Cancel Starlord Macro
This macro will remove your current Starlord buff. You may utilize a simple cancelaura macro to remove your stacks of Starlord if you feel comfortable with knowing when to cancelaura your Starlord.
showtooltip
/cancelaura Starlord
Force of Nature Cursor
This macro lets you cast Force of Nature at the position of your cursor.
#showtooltip
/cast [@cursor] Force of Nature
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
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
Weakauras
Innervate whisper aura: https://wago.io/EkN0SJvYW
For more general Balance Druid WeakAuras you can find a wide range at https://wago.io/dragonflight-weakauras/classes/druid/balance