Fill the barrel, provided in your aging kit, with water to make sure that it doesn't leak.
Use the funnel provided in your kit to pour whiskey into the bung hole on top of your barrel. Reinsert the bung.
Sample your whiskey every month and observe the taste, color and smell so that you can gauge your aging preferences. Add ingredients like wood chips to your whiskey, if you wish, to customize its flavor. Or, you can just leave your whiskey unadulterated, to gauge the effect that the barrel alone has on the taste and smell of your whiskey.
Serve your whiskey in four to seven months. You can generally use the barrel multiple times to age whiskey. Check specific manufacturers' directives, which may vary.