I have a friend that is a private chef for a single family and she got the job through a referral. One of her previous employers recommended her after they asked her opinion/advice in her restaurant.
Also, knowing people with money helps tremendously.
After his death, I was unemployed for 13 months. It took every ounce of resourcefulness for me to construct a new job for myself. I contacted everyone I knew and asked them to contact everyone THEY knew. I submitted a very professional portfolio to all the private chef agencies (and got NO leads from them) and posted ads on craigslist. Finally, I landed a job working for a couple who owned a mortgage business. I was happily employed with them until the bottom fell out of the housing industry. I was laid off, along with all their other domestic help and most of their mortgage company employees. For awhile, they even had their house on the market.
I was unemployed for eight months and finally HAD to take a job back in the kitchen. It is a very difficult time to break into private chef work - according to all the agencies I deal with. Unless you are truly lucky and land a job working for someone too wealthy to be affected by the economy, it may be a long time before you find something steady that pays well. I got a call last week about working part time for a family but when I told them my rates, they never called back.
In summation, my experience has been that finding a successful position comes mainly through who you know. Good luck!
trk is correct...it is a tough time in the economy now. That said...I live in a resort area about half of the year where many folks have second and third homes. I got to know the property managers of high end homes and private estates and can get some pretty good references out of them, top realtors too. Over the years I have developed many great relationships with my clients and they will even fly me across country to cook for them for special occasions or vacations. But that takes time. If you land a gig or family...get to KNOW them, what the kids will and won't eat, any dietary concerns, etc. and REMEMBER it. Get into the family.
If there is a kitchen store near you with a demo kitchen, approach them about doing some cooking classes. I have picked up many clients from my cooking classes. The folks that attend them usually have money and are not afraid to hire a chef, even if it just for a special function or backyard party. And you never know who you will meet at those events.
If there is a Farmer's Market in your area, put up a booth and sell some food. Look good in your best whites and put out a sign saying that you are a Private chef or caterer and see what you get...I landed three weddings last summer from my gig at the Farmer's Market.
Also...make sure you have good insurance, I use Hartford. And get licensed in your state. Good luck.