Craft a map using 8 paper and 1 compass, or find a map in a chest
Hold the map in your hand
Right-click to open and activate the map
Move around to fill in the explored area
Use the map to see your position as the white marker
Craft more paper to zoom out the map at a cartography table
Add another map to copy it
Use a cartography table to lock or expand the map
Keep the map in your hotbar or off-hand for easy use