I hear quite a few guys talking about making their own scent killer and was wondering if you wouldn't mind sharing some of the recipes.

You already mentioned the amount of ingredients:
2 cups of 3% hydrogen peroxide
2 cups of distilled water
1/2 cup of baking soda ( I warm up the distilled water to disolve it)
1 ounce of unscented shampoo or unscented laundry soap