I play Neverwinter on Xbox One and I'm always on the hunt for ways to find astral diamonds. I came across this video that was extremely helpful. The video was made by fnhusa57. His process is straightforward and easy to follow.
Max Out Leadership
This one is controversial for some people. The reason is that leadership tasks take hours to complete. Other professions at level 20 have smaller time requirements. However, these tasks have guaranteed rough astral diamonds.
Use The Trade House Properly
If you research and determine the correct going rate for items, you can always price items to sell. This will be a steady stream of astral diamond income for you. For me, I noticed there's consistently high demand for level five radiant enchantments. Radiant enchantments raised your power statistic. The power statistics is uncapped and why the demand is so consistent.
Get Seals to Buy Orbs and Necklaces
Drake and unicorn seals are very easy to obtain. Just run dungeons as much as possible. The tier two dungeons is where you should focus. When you run a dungeon like Lair of the Pirate King, you will be swimming in drake seals.
Double Diamond Events
I had no idea about this event until I saw this video. Bonus missions rotate. Keep an eye out for astral diamond event. During the event you should think about buying rare equipment for 3 or 4K. You can salvage these for double bonus. This is instance profits in astral diamonds.
Send Letter to Yourself
If an item is unbound, you can send it to yourself through the mail system. I don't rely on this one that much, but it's a really good idea.
What works for you?
The tips above have netted me a lot of astral diamonds. What about you? Do you have some additional things that work for you? If so, I would love to hear what you have to say.