You improve your chances of taking a picture of an immobile insect when the temperature is cooler. On a yearly basis, the best periods are the end of spring and the beginning of autumn. During the day, early morning or evening are best.
If you choose a good period but there is a light wind, your success rate will fall dramatically.
Adjust your camera to burst mode. Sometimes, things happen quickly.
Priority must be given to the aperture mode. It must allow a perfect focus on the insect (especially the eyes) at the same time that it gives you control over what else you want to be in focus in your shot. You might decide that you only want the head to be sharp and nothing else. The aperture mode will help you achieve your goal.
Most photographers prefer an environment empty of what they consider distractions, so that the attention is solely focused on the insect. What you consider a “distraction” is all yours to decide. Personally, I like to modify my approaches and recipes according to the specific goal I am trying to reach when shooting the insect. What you will keep as a background must be useful for the picture.
Naturally, sufficient speed is needed to allow for sharp pictures. Speed is then the priority number two, once the aperture has been set. The minimum speed required is normally 1/250 sec. The use of a tripod is necessary to immobilize the camera. In order to increase your chances, use a remote shutter release when taking your shots.
Aperture and speed being your two priorities, ISO will have to be increased accordingly. A higher ISO will create more distortion (noise) in the picture. That is the price to pay. Different programs are available to lessen to amount of noise, but be aware that using them too aggressively will also affect the sharpness of your picture.
Contrary to what we would normally expect, a sunny day is not ideal for a photo session. You will benefit more from a cloudy day if you want to avoid useless reflections in your shots.
A 100mm focal lens will facilitate your task by allowing more space between you and the insect.
Use manual focus for better precision. In order to verify if the insect is really in focus, use Liveview. When in Liveview mode, enlarge your shot (5X or 10X). You will immediately see if a tiny adjustment is needed to get a sharp picture.
Try to add a touch of creativity (color, composition, angle of view). A black fly on a dark rock, even in perfect focus, is not exactly captivating. Changing the viewing angle works quite well: instead of taking a shot from above, like it is usually done, face the insect with your camera or take it from the ground up.
There are many beautiful flowers at the in Quebec City. While examining the interior of a flower from close up in the picture above, I noticed a very active ant which eventually stopped moving long enough for me to take a chance at macro photography. I used an old lens and got an interesting result.
Needless to say, shoot at least in RAW format. That offers you the flexibility needed to make significant corrections if deemed necessary.