- Shoot, Shoot, Shoot
Really. Remember to hold your camera with you whenever feasible and, just like importantly, shoot with it! Try to recapture as numerous shots as possible. They won't all be keepers, but you'll be getting a lot of good practice that will save you time and improve your shots in the long run.
- Always Ready
Since your camera is at your side (see Tip #1), ensure it's always ready to take a moment's notice. If you're going around and notice an alteration in the light, have a second to readjust your exposure settings so you won't risk missing an attempt because your settings were incorrect and you couldn't change them in time.
- Eye Contact
When you're thinking candid shot, you're almost certainly think a photo where the topic isn't aware they are being photographed. And while that is certainly caused by true, it's okay to recapture eye contact if done appropriately. Typically, the best opportunity to have a candid with eye contact is the split second the topic discusses the camera. When they realize they are being photographed, it's likely they will change their expression and the photo will loose the feel of a candid.
Of course, humans are fairly curious creatures. When we visit a photograph with multiple people interacting, our minds immediately begin trying to piece together what the interaction is all about. As photographers, we can make the most of this by photographing our candid subjects interacting with others or animals–it'll automatically make the shot more interesting to the human eye and mind!
- Take Available Light
For candid portraits, using natural or available light is almost always the best option. Since we're trying to help keep ourselves on the down low, don't draw awareness of yourself and distract your subjects by blasting them unexpectedly in the facial skin with a flash.
The main thing would be to just stay aware and alert–before long you'll start spotting great photo ops before they even happen!