I gathered clear glass vases that have accumulated over the years and poured about 1/4 cup of white acrylic paint inside each one, and rolled them around until the paint completely covered the glass. I then inverted them onto a paint tray and let the excess paint run off for a few hours. The last step is to remove the paint that's left on the rim and then you're done.
You can still use these vases for fresh flowers by putting a small glass inside.
This project cost me nothing which is my favourite amount to spend. Little things like this ramp up my happiness more than I can say.