Rinse your vase with water and use an eco-friendly soap with a scourer to properly clean the in- and outside of the vase. Make sure to also clean the rim of the neck and the bottom of the vase. Give extra attention to possible water stains from the water level. Every time when you refresh the water, make sure to also clean your vase (every two to three days). Also clean the vase before you place it back in the cupboard after use. 

Take care of your flowers by nicely placing them in the vase with enough space, and always cut a bit off the stem beforehand. Every time when you refresh the water, cut a bit off the stems again, allowing your flowers to take in as much water as possible.