if you have a pinterest, im SURE you have seen this one.
*acrylic paint is super cheep, i got a 8 bottles for 60 cents each at micheals.
make sure the glass is clean first, then you can pour a small amount of your color into the container. if it has a small opening, pour some in and hold a folded papertowel over the top and move around. if not, then you can paint it with a brush or not. figure out what you like. let dry, and you can use for decorations together. enjoy!