Hint: there’s no need for fancy equipment to make artfully designed cakes!
Put a resealable plastic bag into a cup or Mason jar, with the corner of the bag pushed to the bottom of the cup. Using the cup to keep your bag steady, add your frosting to the bag. (If your bag is much larger than your cup, you can fold the bag over the sides to make the process more comfortable.)
Pull the plastic bag out of the cup, and twist the top so the frosting is pushed down into the corner of the bag.
Cut the tip of the plastic bag (the smaller the cut, the smaller the piping), but be ready! Some icing may want to pop out if there’s too much compression!
Using a circular motion with a gentle squeeze, frost your cake, cookie, cupcake, or whoopie pie. Awesome job! You are officially piping frosting like a pro!