In my experience I have found that they are easier to photograph from a bridge over a river rather than a larger expanse of water as they tend to stay within the confines of the river banks and you can also get nearer to their flight level.
The other thing that I have noticed through observation behaviour-wise is that they '' hawk '' Dragonflies '' like birds of prey. In this connection I attach an image that I got as a record shot with sincere apologies for the quality.
I have also seen them hawking over meadows in the late afternoon and early evening rather like Swallows
Just starting a dive
I am not usually a fan of '' head-on '' images but in this case I rather liked the composition
I may be wrong but I think the fish is a Pike
Hawking a Dragonfly - a record shot taken hurriedly at long range, apologies once again for the image quality.