Ammunition, food, and med-kits are vital in the fight for survival in The Final Station. Food is used to feed passengers on your train, med-kits can be used to heal yourself or your passengers, and ammunition is sparse but useful for taking out those pesky zombies.
Whilst all three can be found by exploring every corner of each outpost and station, you can also craft med-kits and bullets when you are on the train. The crafting hub is near the front of the train, where you speak to other characters and view your location.
On the left of the pop-up box there will be four small boxes that you can highlight by scrolling with the left thumb-stick. The crafting option is the third one down, as shown in the image above. Here you will be able to craft med-kits and ammo for your weapons.
You should scroll right to highlight the option you desire. Select it and then select ‘craft’ when it appears. Doing so will use the items you have found on your adventures to craft items to heal you and your passengers, or to help you take out more zombies at the next stop.
That is how you craft in The Final Station. It is very useful to know how to craft early in the game.