OK, here are two tips for better flower images. Change your perspective. Most of us take flower photos looking down on them. Boring 😉 – many times.
Why not get down low. In this image to the left, I shot from a position below the flowers and used the sky as my backdrop to emphasize the flowers. Be careful of the exposure. The sky will fool your autoexposure mechanism and the subject will be underexposed. So, use your exposure compensation dial to properly expose the subject – some trial and error is in order and be sure to watch your LCD panel.
Tip #2: get close and fill the frame. The second image (of a Rose of Sharon) was made with my Canon 300 L IS f4. Its close focusing ability allows me to get close especially on larger flowers.
You can also use a macro lens to explore your flower subjects. Be sure to use a tripod. High overcast days are best for nice even light: it’s light using a giant softbox.