Find someone who shares your vision. You'll need to be able to communicate effectively with your partner to make decisions, set goals, and drive the business forward.
Don't duplicate yourself. Find someone who's like you, but not too like you. They need to fill holes in your own experience or expertise, but if you are too similar you might end up at loggerheads.
Sneak a peak at their Rolodex. Are they well connected? A partner with a strong business network, industry connections or client list can help increase the value of your business and improve your chances of long-term success.
Protect yourself. Share the financial commitment as far as possible: a partner is less likely to get cold feet and do a runner if they've invested a wad of cash in the business. Impose legal safeguards, too. These days, formal partnership agreements are as common as pre-nups.
Ask around. Are they tried and tested? Credibility is important. Don't be afraid to ask hard questions: if their last business failed, find out why.
Be coldly objective. Evaluate candidates with an impartial eye - enjoying a pint with someone doesn't mean you could run a business with them.
Take your time. You can't get to know someone in a single conversation. You might not even get to know someone in successive conversations over a couple of months. There is no 'love at first sight' in business.