With the right materials you can craft smaller items, like medkits and throwable explosives and bigger things, like weapons or vehicles.
Some items will require you to upgrade your homebase Facilities to a certain level before you can put them together.
To start crafting items, you will need to gather materials. You can find them while exploring or get them from trading.
Vehicles can be crafted in the Garage (cars), Harbour (boats) and Helipad (helicopters).
If you have your heart set on crafting a specific item, you can Track materials required to make it by highlighting the item and pressing the assigned button. The material tracker will appear in the top right hand corner of your screen.
Let us know if you have any other questions!