First off, admit what you don’t know. The client hired you for your expertise, not your omniscience. Telling the client when you don’t know something has two benefits. First, it gives you the opportunity to make and keep a micro-promise (“I’ll find out for you”). Secondly, it makes the client feel wise: they’ve thought of something you haven’t.
Find common ground. It’s about what you and your client share, not what you exchange: the relationship between the two of you is more important for generating long-term business than the actual work you’ve contracted to do. So don’t focus on the work without the frills: establish a relationship with your client. Invite her out to dinner. Take him to a baseball game. If clients enjoy working with you, they’ll bring their business back.
Make micro-promises. Every time you keep a promise, your trustworthiness inches up. So make promises wherever possible. You don’t have to promise the earth – it’s enough to say “I’ve got an article that might interest you – I’ll pass it on,” or “I’ll get you the name of our translating service”. Note that this tactic will backfire if you don’t keep every one of your promises. Nothing erodes your integrity faster than saying you’ll do something you then leave undone.
Don’t be disrespectful of your competition. If you’re working for McDonald’s, don’t slam Burger King. Even if your client badmouths your competitors, don’t get in on the act. Showing respect for your competition raises your own worth in the eyes of others, who will wonder how you’ll speak of them if you don’t get their business.
Speak your client’s language. If he calls a pack of presentation slides a deck, call it a deck. If she calls weekly meetings jours fixes, adopt the French expression. The more you use the client’s vocabulary, the less foreign you seem.
If you ever expect to do business again – and, as the German saying has it, you always meet twice in this life – then look to the medium term, even when doing so isn’t in your immediate interest. Turn down work if you’re not best qualified to do it or don’t have the capacity to do it well. Doing so has two advantages. First, you’ll astonish your client and cement your reputation for integrity: when more work comes up in the medium term, you’ll be the one she thinks of first. Secondly, turning down work gives you the opportunity to refer business on. Especially if the work you’re turning down isn’t in your sweet spot, recommending someone else means he or she will owe you a favour – one that’s likely to turn up in the form of work for you further down the track.
Go out of your way to maintain your relationship after the assignment ends. That goes well beyond Christmas cards or birthday wishes. Search out articles that might be of use to them, and clip and send them on. Read their trade magazines, and call them about new developments in their industry. (You can set up a news watch on their company via Google Finance, if they’re publicly listed.) If you keep calling when you have something to offer, they’ll take your call when they have something you want.
At the end of the day, while there’s no relationship without high-quality content, there won’t be much more content coming your way in future if your relationship with your client doesn’t flourish.