After completing the game, you'll get a prompt to save your game post-credit. Perform a manual save on a separate slot. The next time your main menu appears, you'll see the New Game+ option. This option allows you to start a new game and keep all the weapon upgrades, learned skills, unlocked weapons, holsters, and recipes for your playthrough. When playing as Ellie, you'll be able to have complete access to your weapons and recipes once you've reached Seattle Day 1. For Abby, you'll start off with your complete set from the start.
REMINDER: It is very important to save the "cleared" save file. If you failed to save the clear file and loaded a different file, you'll have to go through the normal story progress and finish the game normally to be able to access the New Game+ option again.
This option is available from the main menu as you progress through the story. However, you have to be careful since selecting a chapter will overwrite your current auto-save; make sure you save your current progress in a separate slot to be safe. Chapter Select is useful for replaying previously-completed missions in case you missed some collectibles. This feature also has a breakdown for all collectibles found in specific chapters and missions.