You see photo-ops every day: governors and presidents signing bills into law, Hollywood stars on the red carpet for the premiere of a film or a football owner signing a free agent to a contract.
Here are some tips:
1) Location and lighting
To a photographer, lighting is everything.
Indoors isn't always an advantage here. What seems like perfectly good lighting usually isn't enough for photographers -- and it's hard getting flashes to work well indoors without making who they shoot look washed out, especially if the ceilings are low.
In the age of budget cuts, many newspaper reporters and bloggers shoot their own photos and video, often with point-and-shoot cameras that aren't as capable as the big digital SLRs used by full-time photographers. You have to account for that.
Pick a room with high ceilings and enough space. If the weather is good, outdoor shots look better. It's smart to have two possible locations, depending on the weather.
2) Action
Even if your location and lighting are perfect, the photos will be boring if it's a group of people standing around while they grin at the camera. Nothing is more cliched.
Any kind of action is better than people standing around. That's why you see the lottery director handing over a giant check to the winner, sports team owners giving their new star a team jersey and presidents and governors handing out pens when they sign a major bill.
3) Details
The background of the shot matters. Avoid anything distracting. This is why many media events these days have a curtain with a repeated logo or slogan. It serves two purposes: controlling the background and reinforcing the message.
You can see plenty of bad examples of not controlling the background when TV reporters are covering breaking news on a city street and people mug for the camera behind them, or at political events when protestors show up to get behind the shot to wave signs and chant loud enough to drown out whatever is said.
Finally, photographers need to identify everybody in their photos for the cutline (the text under a photo). It's a smart idea to have a one-page handout with the correct spelling of everyone's name, their title and anything else relevant about them. along with a fact sheet.
If you know a photographer, or have an amateur photographer on staff, do a walk-through the day before to identify any problems.