In one sentence, describe what the following article is about:

Place the glasses on a bar or table, and measure the tequila into each glass. For a drink that isn't as strong, only use a quarter or half ounce (7.5 or 15 ml) of tequila. For a stronger drink, use a full ounce (30 ml). To make coffee tequila poppers, use a small serving glass instead of a shot glass. Add a few ice cubes before pouring in the tequila. Pour in equal parts coffee liqueur. Use equal quantities of soda based on the amount of tequila you used. Feel free to add grenadine at this point if you aren't making coffee tequila poppers. Popular lemon-lime sodas include Sprite, 7-Up, Sierra Mist, and Blue Sky. To make a coffee tequila popper, fill the rest of the glass with lemon-lime soda. You can either slam the drinks to make them fizzy before serving them, or you can serve them now and let the guests slam their own drinks. To make the tequila poppers and coffee tequila poppers fizz: Cover the top of the glass with your hand, a coaster, or a napkin. Carefully slam the bottom of the glass down on the top of a table or the bar. The impact will activate the carbonation in the soda. Serve and drink the tequila popper while it's still fizzy and foaming.

Summary:
Set up your shot glasses. Add the soda. Serve the drinks.