Moving in close and using a wide aperture is a technique that I love to use - creating a diffusely-blurred background. Just because your background is blurred does not mean that you can ignore what is in it. Here I attempted to place background sunflowers in composition-enhancing positions in the frame.
A circular polarizer filter was used to create the deeply-saturated colors - and to obtain a shutter speed within the cameras capabilites (by reducing some light).
Camera and Lens Settings
35mm f/1.4 1/4000s ISO 100 5616 x 3744px