Tomorrow is the first Great Vault of Season 3, and you'll want to fill up your Vault to get a chance of Tier! The Great Vault can contain Tier in any slot, so the more slots you complete, the higher chance of Tier. Starting off the a piece of Season 3 tier is a huge bonus if you manage to get lucky.
If you want the highest chance of getting tier, make sure to fill up all 3 slots on the dungeon row and 3 slots on the Delve row. You can complete easier content (Heroic dungeons or < Tier 8 Delves), to try to roll tier, but the rewards will be lower item level.
