1. Go Professional
Spend the money. it's worth it. Go to a professional who is trained, understands lighting and takes headshots for a living. Don't approach a friend who happens to have a decent camera. Hiring a professional will actually save you both time and money in the long run while delivering top-shelf results.
2. Go for Personality Over Glamour
Casting directors expect you to look just like your headshot and will be unenthused if you show up looking totally different. Headshots are about representing your type; age, wrinkles and all. That being said, a professional headshot photographer can help you capture subtle aspects of your natural character that will set you apart from your competitors.
3. Find a Photographer that Gets You
You have to vibe with the photographer. You'll be using these headshots for a couple of years. Ask for a consultation, get a feel for how they photograph your type, your ethnicity, gender, etc. Being comfortable in your photoshoot is essential to produce headshots that portray a depth of character that will inspire casting directors to give you a call.