Making you flowers last longer

We often get asked what's the best way of making stems last a longer. Almost everyone I meet has a different tip on the subject so it's tricky to know what to tell people. Also some stem need to be treated differently to others.
There are lots of 'old wives' tricks like lemonade, a penny in the bottom of the vases, sugar in the water, to name but a few but personally I can't advocate enough, fresh water, this is what they would be drinking in there natural habitat after all. We tell people to try and change the water every couple of days. The best way to make sure this isn't too big a task by not filling your vases to the top with water. If your changing it often the vase will never run dry and quite a lot of flowers don't like to be up to there ears in water! Things like callas, gerberas and tulips have soft delicate stems so will absorb water into the stem disintegrate and make them all soggy and slimy! Nice! this also means that the water gets very dirty and extremely smelly.
Making sure that the part of the stem that is in the water is free of leaves. Leave have a lot of 'bacteria' on them. Not horrible crawly bacteria, just dirt from the environment that they have grown in or transported by. So leaving the leaves in on the stem and sitting them in water will make you water dirty very quickly. Also re-cutting the stem really helps. When flowers are out of water for any length of time they dry over at the ends which makes sure that they don't loose any water but also means that no water can get in. SO re-cutting the stem before you put them in the vase is an absolute must. Also after you have changed the water it's a good idea to re-cut the stem as if the water has been dirty the stems will seal over and that seal needs to be opened. You don't have to cut much off unless they have been out of water for a long time.
Cutting 'woody' stems- thick robust stem at an angle will create a bigger surface area and so give the stem a better chance of getting plenty of water. Soft stem flowers can be cut straight across as they have no problem drinking and in some cases like gerberas and tulips are quite greedy with the water that they drink which is why their heads often flop over.
Also making sure that the place that you are putting the flowers is as cool as possible, not next to a radiator or in a draft if possible.
Enjoy!