Step 1: The Clothing
You will need:
-Long sleeve off-white henley shirt. Example style here.
-Cargo pants (can be olive green or even tan). Some suggestions here and here
-Basic brown belt
-Brown boots. Example style here.
Step 2: The Accessories
-Plaid blue scarf. This can also be gingham print. There is a great version here.
-Black cord and silver ring
-Brown leather bag/backpack/harness. The one I'm wearing is here. Good ones here and here too.
-Leather wrist cuff. Great version here.
-Drake's journal - miine was made using an old instruction manual and burning parts of the edges and front/back cover.
-Fake gun (surplus stores or toy/hobby stores are great places to look). One suggestion is to get a toy gun and just spray paint it black
Now you're ready for an adventure!