Multiple Exposure, Dreamlike Roses
You can create a painterly, almost dreamlike effect without any post production tricks. This was done in-the-camera by enabling the multiple exposure mode. While not every model has this feature, you may be pleasantly surprised to find it buried in the depths of your menu. There is no right or wrong way to do this, so feel free to try my method or experiment with your own.
The first shot was captured in the traditional manner, with everything in focus and well exposed. For the second image I slowed the shutter speed down to about 1/4th of a second and quickly moved the camera towards and away the flowers. The camera then stacks these two images together with the result shown here.