Stock Up On Chunks and Slabs
Before heading into Ashes of Ariandel, you might want to consider leveling up a bit. You can jump into the DLC area once you’ve unlocked the Cathedral of the Deep main bonfire, but it’s better to prepare yourself first before going in. To start, make sure that you have a +10 weapon to ensure that you’re dealing the maximum amount of damage your build is capable of. I would also recommend trying to hit level 70 before going in, as the enemies and bosses are way more ruthless than anything you’ve encountered in the base game.
You should also consider stocking up on Titanite Chunks so that you can upgrade any new weapons that you find in the Painted World of Ariandel. If you can, set aside your Titanite Slabs and save them for any DLC weapons you might find yourself attached to. There are only a few Slabs that you can obtain in each game cycle, so don’t use them carelessly. Collecting all Estus Shards to ensure that you have the maximum number of Estus Flasks before going in would also be very wise.