Cymbidium Orchid leaf

If anyone knows how to have these flower more than once, please share. We have seven of them, which have flowered once in their lives. They are given orchid growth and flower fertiliser at the relevant periods, kept cool at night and warm during the day, all to no avail...

Taken with the Jumbo lens, tubes, and extender, shown in an accompanying image. It means you can be several feet away from the object - between six and twelve, and appear as if you are looking through a very powerful telescope.