Lex and Christopher discuss West Marches campaigns--a style of campaign that features wilderness exploration and player-directed action. Everything from scheduling, to party makeup, to game session objectives is up to the players!
Check out Lex's Tales from the Yawning Portal Campaign
Sharkbone - Using the Sandcastle
Welsh Piper's article on hex-based campaign design
You can get hex paper at the scales recommended in the DMG that you can print out.
Learn more about the West Marches from the source!