Gaining Energy
All three of your primary spells generate energy. Each Wrath you cast generates 13 lunar energy, while each Starfire generates 20 solar energy. Starsurge generates either lunar or solar energy depending on your current state. If you are heading towards a lunar eclipse, Starsurge generates 15 lunar energy, while if you are heading towards a solar eclipse, Starsurge generates 15 solar energy. If you are in a neutral state, Starsurge generates 15 solar energy.
You can tell what state you are heading towards by looking at the small arrow on the energy bar. If the arrow is pointing left, you are heading towards a lunar eclipse, while if the arrow is pointing right, you are heading towards a solar eclipse. If there are two arrows on the bar and your energy is at zero, you are in a neutral state. Casting a spell that would generate energy opposite to the direction you are currently heading towards has no effect. For example, if you cast Wrath while you are at 35 energy and you are heading towards a solar eclipse, you will remain at 35 energy and your direction won't change.
Eclipse States
While you are in an eclipse state, the damage you deal with a specific category of spells is increased by 25 percent before level 80 and by a minimum of 41 percent at level 80 or above. The damage bonus increases depending on the amount of mastery you have.
A lunar eclipse increases the damage dealt by your arcane spells, such as Starfire, Moonfire and Starsurge. A solar eclipse increases the damage dealt by your nature spells, such as Wrath, Wild Mushrooms, Hurricane, Insect Swarm and Typhoon. if you have placed a point in the "Sunfire" talent, your Moonfire spell will turn into the Sunfire spell, allowing it to also benefit from the solar eclipse damage bonus.
Basic Spell Rotation
When beginning a fight from a neutral state, cast Insect Swarm and Moonfire on your target, then cast either Starfire or Wrath depending on whether you want to head towards a solar or lunar eclipse. If you are beginning the fight with some energy already stored, whether you cast Starfire or Wrath should depend on the eclipse state you are currently heading towards. After your first cast of Starfire or Wrath, cast Starsurge, then continue casting your chosen spell until you reach the eclipse state, at which point you should switch to the other spell to begin working towards the other eclipse state. Continue casting spells and switching between eclipse states, casting Starsurge whenever it is available and refreshing Insect Swarm and Moonfire whenever they disappear from your target.
Lunar Shower
If you have placed points in the "Lunar Shower" talent, you will gain a buff increasing the direct damage dealt by your Moonfire and Sunfire spells and reducing their mana cost. This buff can stack up to three times and will greatly increase the damage you deal with these spells. However, the buff also causes your Moonfire to generate eight solar energy and your Sunfire to generate eight lunar energy, causing you to leave an eclipse state much faster than you otherwise would.