Build planner
Mining at level 20
The setup that gathers the most at your level, from everything on the wiki: judged by how long each gather takes, the chance it succeeds and the drops it gives, at the node you pick. Put your own piece in any slot and the planner builds the rest around it; save it to keep it and share it.
Tool
Its power decides which nodes you can gather: 8 reaches everything up to the Nickel Ore DepositWhy: Tin Ore Deposit needs only power 1, and this build reaches the limit there, so Lucky Crusher's luck counts for more than more efficiency.
Other pick: The Juicer (Lv 8: 15.5 efficiency, no luck; 10% less a minute here)
Armour and accessories
One of each; rings twiceWhy: The only helmet on the wiki that helps Mining. Past the limit at the Tin Ore Deposit it adds nothing; it counts on stronger nodes.
No chestplate, leggings or boots on the wiki help Mining. Wear your combat set.
Why: The most efficiency any gloves give. Past the limit at the Tin Ore Deposit it adds nothing; it counts on stronger nodes.
Other pick: Dusty Gloves (Lv 4: 7.5% efficiency; about the same here)
Why: The most luck an amulet gives here. Luck is a chance of a second drop on each gather.
Other pick: Rookie Miner Amulet (Lv 10: 7.5% XP, no luck; 10% less a minute here)
No ring or greaves on the wiki help Mining.
Pet, elixir and food
No pet helps Mining. The Pet Glossary's skill pets help Farming and Fishing. All pets
+5 Mining Efficiency, added to the flat total. Permanent. Counted at its top level: it isn't in your elixirs yet.
+49.5% Mining Efficiency and +22.5% Mining XP for 3 hours. Each star adds 10%.
Guild and collections
Not countedYour guild's upgrades and your collections add efficiency and XP, but the planner can't know yours. Turn them on to count them.
The Tin Ore Deposit: its page, with its drops and where it is.