To get a really great and quick lip stain, all you have to do is go to your kitchen. If you have a box of red Jell-O then you're in business. If you don't have one on hand then you can grab a small box from your local grocer for only a couple of dollars. The best flavor to use is Strawberry or Cherry, because they give the best natural red stain.
Once you have your Jell-O, take a small container (with a lid) and empty the Jell-O into it. You have several options on what to use to apply the Jell-O to your lips. You can always use your finger, but if you are worried about staining your fingertip then you can use a Q-Tip, a clean eyeshadow applicator, or a lip brush.
Once you have decided what you will use to apply the stain, you may begin. First slightly wet the item that you will be using to apply the Jell-O with water. Then dab it into the container of Jell-O. Now you can apply it to your lips, but make sure you lean forward slightly when you apply it because some of the Jell-O crystals may fall downward. All you have to do is rub the applicator back and forth on your lips, just as if you were applying a lipstick or lip gloss. Try to make sure to stay within your lip line so you don't stain the area around your mouth, giving you a Kool-aid effect.
Once you apply the Jell-O to your lips, rub them together. If there are left over crystals on your lips then you can buff them off with a cosmetic wedge or clean Q-tip. Now look at your lips and gauge the level of stain. If you want more color, you can apply a second application. Just make sure you don't go overboard with the staining. It should be used to color your lips and make them seem natural. Your stain should allow you to wear a little lip liner, if needed, and a touch of lip balm or gloss. The great thing about lip stain is that you can use it under lipstick as well, so when your lipstick wears away you will still have a beautifully stained lip.
As a bonus, once you get the hang of staining your lips with Jell-O you can get creative by taking a small amount of balm, such as Smith's Rosebud Salve(Compare Prices), and mixing it with a small amount of Jell-O to create a gloss-like stain. Once you get the hang of mixing the correct amount, you can also use it as a nice cheek stain too.