My first guide. Please let me know what you think. My hopes is that writing what has personally worked for me will make me a better Smite player as comments and constructive criticism will come. I'll do what I can to update it as often as possible. Feel free to share on what works for you and any Gods you have a difficult time dealing with as Chang'e.
Concept
The most important thing for Chang'e is to get her cool down reduction (CDR) to 20-30% as quick as possible using Chronos Pendant/Breastplace of Valor and Spear of Desolation so your offense can take off and you're able to stay in the fight longer due to Shoes of the Magi and Lotus Crown. Your main damage items will be Rod of Tahuti, Spear of Desolation, and Obsidian Shard.
Your goal is to target characters with 50% health. Blink will help close the distance and Rod of Tahuti will give you the power you'll need to get the kill.
Early Game
Your early game strategy should be to stay safe and level/farm to build Chang'e until you get your Chrono's pendant/Breastplace of Valor. Chang'e's passive will allow you to purchase items while in lane so Shoes of the Magi and her 3 ability will keep you in lane. The only thing you'll need to worry about is mana consumption.
Mid Game
At this point, you have the damage and CDR. Once you have your Rod of Tahuti, your 3 ability should heal you and your allies a lot. Spear of Desolation and Chronos Pendant should bring you at or above the 40% CDR gap. Do not be afraid to blink to an enemy to stun them with your 4 and follow up with your 1 & 3 ability.
Late Game
Late game is all about the team fight. Lotus crown helps with that as it'll give your team the physical & magical protections when you heal them with your 3. At this point of the game, your top priority should be about sustaining your team with your 3 ability, stunning enemies with your ultimate, and last should be dealing damage to enemies.
*Depending on the situation, you may get Lotus Crown before Spear of Desolation
*Depending on the situation, if an ally already has Lotus Crown then you could replace it with another item. (I would recommend an item that deal with movement like Doom Orb, Gem of Isolation, or Charon's Coin)
Flat pen and percentage pen should be in that order and a little earlier; here are my 2 build options.
Mage's Blessing > Shoes of Focus > Spear of Desolation > Obsidian Shard or maybe Charon's Coin > lotus crown > Rod of Tahuti > sell blessing for Chronos' Pendant > sell boots for Rod of Asclepius, Doom Orb or Ethereal Staff.
Or
Mage's Blessing > Shoes of the Magi > Chronos' Pendant > Divine Ruin or Spear of Desolation > Soul Reaver > Charon's Coin > sell blessing for lotus crown > sell boots for Rod of Tahuti.
This builds use mostly the same items with a more efficient power curve overall, give them a try if you'd like. I could also give you some help with her Solo builds if you're interested in adding them again.