google flower photography like this
Lighting is obviously a foundational and critical aspect of flower photography and any photography. If you don't have the book already I would recommend
Light, Science and Magic. Imo and many others, this is the bible of lighting principals. Once you understand how light really works and reacts, you can do whatever you want with it.
That being said, when I googled 'flower photography', what struck me as of utmost importance is the treatment of the flowers. Flowers come in all shapes, sizes and colors. One type of framing, depth of field, angle, exposure, and background on one type of flower might look great, but on another might look like total a$$. I know this is true on everything, but it really stands out as an issue with flowers for me. They are strange shaped objects and differ dramatically in their formal qualities. For instance, with really intricate busy looking flowers, you might want a very shallow depth of field and to focus on only one flower in the bunch--if you were to focus on the entire bouquet it would be too busy and distracting looking. Something like a lily, I might try to really try to exploit its streamline bottom bulb shape by lighting is as dimensionally as possible. Flowers with a sun burst like shape and rounded petals, I might play up the uniform and almost graphic shape by shooting it straight on. Flowers are beautiful objects, but I think they need careful work in how to best exploit their unique qualities.
Good luck!