If you are first starting out in photography, it might seem rather difficult to capture a shot like this. But observing the behavior of the insect and choosing some targeted setting can make this shot an easy one.
When I arrived on the scene, I noticed this beautiful butterfly. He returned to the same flowers again and again, enjoying the last remaining dew. So, I set up my camera near one of his flowers. I chose an angle that accentuated the lovely side-lighting, and a flower that saw sufficiently separated from the background to five me a good background blur. After manually setting and locking the exposure, I mounted the camera on my Induro BHL1 ball head and focused on the tip of the flower. I took a test shot to ensure that the entire flower was sharp, and then waited for the butterfly to arrive. When he returned to the flower, I was ready to fire away.
It might help to mention that while I was setting the focus (before the butterfly arrived), I left my BHL1 ball head loose and used it as a gimbal head. That allowed me to adjust the framing and also make minor changes to the focus if necessary. I used the same technique for this shot of a damselfly. I watched her for a few minutes as she flew, and then chose a spot to set up my camera. I was ready then she landed. I re-framed quickly, set the focus on her eyes, and released the shutter.