Filling a liquor flask can be a complicated, messy procedure for the inexperienced. However, with a few simple techniques, you can learn how to fill your flask without any needless spills.
The first thing you should do is make sure your liquor flask cap is unscrewed and out of the way. Most flasks come with an attachment to the cap, making the cap itself hard to lose. Just make sure the cap and its attachment are unfolded all the way, or turned so that you have clear access to the flask's opening. You'll probably notice immediately that the opening to your flask is quite small, usually no more than half an inch in diameter. Herein lies the true challenge of the entire process.
It strongly recommended that you obtain a funnel of some sort before continuing. You're likely to spill if you rely solely on a steady hand. A typical, plastic kitchen funnel is an ideal tool for this process but if you don't have one, there are ways around that. Any small, firm paper lying around the house can be used to make a temporary funnel; it's best to use something like an index card, an old greeting card or a pamphlet.
This is a trick which also comes in handy if you need to top off your motor oil in your car and find yourself in need of a funnel: take your card or paper and roll it up at an angle so that you end up with a cone shape (the sharper the angle of your roll, the smaller the pointed end will be). Now, place the pointed end securely into your flask so that it stands up by itself. Check to make sure you rolled your homemade funnel tightly enough so that the liquor won't leak out along the side. Once that's done and your flask is sitting on a steady surface, you're ready to pour.
Using one hand to hold the flask, take your liquor of choice with your free hand and slowly pour it into your funnel. Be very careful not to overwhelm the funnel and, subsequently, the flask - especially if you're using a homemade one. Keep in mind that most flasks will only hold one-half to 1 cup of liquor. Once you're done, dispose of or rinse your funnel.
Make sure the cap attachment is folded back and the cap is screwed on tight. Once this is complete, you're all finished! Now, you're ready for a smooth and discrete experience with your liquor flask.