For many of the Tulip photos presented here I chose to shoot them at a larger aperture in order to have only a very small amount of the flower in focus. This helps to not only make the background a more pleasing blur of colors, but also draws attention to a particular flower or a specific part of them.
Another technique I really enjoy is to position my camera under the flower and look up at it towards the sun. This gives the appearance that the flower is being lit from within.