How can I get the most from New Game + ?
The addition of a New Game + mode to Dishonored 2 finally allows players to carry over progress from one playthrough to another, but you can't take it *all* with you - here's to maximize what you start with in a New Game +.
First off- items, upgrades, ammo, and coin do not carry over. Blueprints themselves do, though you'll have to repurchase the associated upgrades from the blackmarket. If you used this guide to find all 25 blueprints, you'll start ready to equip yourself with the best gear for your new playstyle.
Powers and enhancements don't carry over either, but the Runes you committed to them do- if you sunk 5 runes into the Bend Time ability, that's an extra 5 runes you'll have at your disposal in the next playthrough. Oddly, any Runes you're carrying at the end of the game which haven't been spent on powers or enhancements are simply lost, so be sure to use them all before completing the game. (Note that, in New Game +, there are no power restrictions- Emily can purchase Bend Time, Corvo can purchase Far Reach, etc).
Bonecharms do not carry over, but any traits you learned by mashing up bonecharms do, allowing you to craft some pretty powerful charms right out of the gate.
The optimal strategy for setting up your New Game+ is to use this guide to find all the Runes and Bonecharms, and scoop up all the whalebone you come across. Buy the Bonecharm crafting power, but don't actually craft any new bonecharms during your playthrough. Buy the Rune crafting power sometime before the end of the game and then, just before your final victory, grind up every charm you own, and use this mountain of whalebone to make as many Runes as you can, before spending them all on Powers and Enhancements. My record is 68 Runes carried over, but I suspect there's enough hidden whalebone for a few more.
If you have already completed the game but didn't commit your Runes, you can play the end over again and do so. Just be sure to let the credits roll completely- otherwise your previous ending may not be properly overwritten. Alas, this is a little tedious to test, because you don't know for certain how many Runes have carried over until you reach Mission 2 of your next playthrough.
If you're in doubt, you can quickly zip through Mission 1 to check. The Streets of Dunwall section is particularly easy- just sprint down the road without stopping and swim straight out to the Wale.