1. Quote early and honestly
The biggest potential conflict in any business relationship is what you charge for and what your client will receive. Make this plain at the earliest stage possible. Give a clear quote, in writing, and list out what you will deliver, by when, and any fees for revisions or edits.
2. Question, question, question
Many clients won't be used to dealing with designers, and so will have an expectation that you will instinctively know what they're after. Don't fall into the trap of believing this - question a client on everything: their expectations for the job, goals, deadlines and more. You can never have too much information.
3. Talk to the right people
Make it clear that you require direct contact with the decision makers, and make sure they're aware of why clear communication channels are important. Reinforce this by ensuring your own communications are punctual and professional; clients are busy too, so group questions in to a single email rather than several separate ones.
4. Give regular updates
Giving a client regularly scheduled updates will not only keep them involved, but will make them aware of any potential delays and bottlenecks. Agree due dates for drafts and always submit what you have, regardless of whether it's finished or not. Sometimes a client needs to see the individual design stages to truly understand the designer's task.
5. Anticipate feedback
Ask a knowledgeable friend, colleague or even an old client for feedback on your current project. You don't necessarily have to heed their advice, but note down the points they pick out. Chances are your client will single out the same elements, meaning you're prepared to make suggestions to resolve any issues as and when they come up.
6. Be timely
Keep your client aware of any issues you run into that prevent you from hitting a deadline. Most clients will have no problem pushing back a deadline because of unforeseen circumstances, as long as they are made aware of any problems when they happen rather than after they happen.
7. Learn to say no
Clients appreciate honesty - even if it takes a while for them to realise it - so be clear and frank. If something's a bad idea, say so. If a client asks for too many revisions or a complete reworking, make it clear how much extra you'll charge. This is your profession, and your time and skills cost money.
8. Only give advice when asked for it
One of the biggest client complaints made against designers is overstepping a remit. If you've been asked to build a website, then that's your brief, nothing more - not to rebrand the company, nor to suggest strategy or give business advice. Designers hate it when clients suggest design tweaks, so respect your client's expertise at all times.
9. Use examples where possible
Nothing tilts a case more than precedent, so use it to your advantage. If a client struggles to understand your ideas, show them a range of existing designs - either of your own or someone else's - that prove you point. Explain why such design solutions will work for them, and project the success of your example upon your client's business.
10. Put it all in writing
It goes without saying that a legally binding contract, purchase order and any copyright and ownership information is agreed from the beginning. But do make sure you confirm important discussions in writing. If a client calls to say they'll pay you extra for a bolt-on job, confirm it over email to avoid invoicing disagreements and the potential loss of future work.