No foliage in the water. When you put your flowers into a vase, there should be no foliage below the water line. Submerged foliage encourages microbial growth that will clog the stems and prevent them from absorbing water.
Use a clean vase. Wash your vase with soapy water and rinse it well. Fill with warm water and if possible, add a packet of flower food. It feeds the flowers and also minimizes the growth of bacteria and other microbes in the water.
Make clean cuts. Use a sharp knife or scissors to re-cut each stem right before it goes into the vase. Cutting on a slight angle will increase the surface area for water uptake. If you wish, you can make the cuts in the sink under water. This will ensure air doesn’t block the water-conducting tissues at the end of the stem.
Keep them cool. Always keep your flowers away from heat and direct sunlight.
Refresh the water. Watch the water level and replenish it as needed. After a couple days, check to see if the water looks cloudy. If so, remove the flowers and remove the old water. Rinse the stems under running water and cut about an inch off the bottom. Clean the vase and refill it with fresh water and flower food.
Edit as needed. Some types of flowers last longer than others. To keep your arrangements looking good, just remove any spent flowers or wilted foliage. As the size of the arrangement shrinks, you can transfer it into a smaller vase.
If your flowers came in a pot, basket or other container with foam, add fresh water every day.
Everlasting flowers care. Do not wet your arrangement. Keep away from damp places and avoid placing them in direct sunlight.