You get your design instructions from your client and then proceed to start the design. This sounds like the perfect scenario. You are given a gem of a website to develop, and it is going swimmingly. Everything is slotting into place like it was meant to be UNTIL your first meeting with the client. It doesn’t matter what they agreed to the first time around, even if you had every item listed and agreed to in writing.
When they return, they have probably talked to every family member from the 9 year old through to the grandmother and each has put in their 5 cents worth. The client has a completely befuddled view of the site now and has probably changed their mind with each discussion. Whatever they have been told is now in conflict with their original outlook and agreed on the format.
If you have your original signed agreement, it is a very good idea to have this as the basis of your backup argument for the website and for the work you have put into it.
I tend to have learned over time that clients think it is easy to change every single thing agreed to. This is one of the reasons I get the original document down in writing with each point listed and agreed. I know it tends to seem cold blooded, but it is a great protection for your work.
Take this document and before the meeting (I usually do it as I design) make sure you update each section with your reasons for doing each step.
This way they can see the flow of the design and see why each step is necessary. When they see this, they are far less inclined to want you to reverse back 20 or 30 steps to change something because junior though it might be cool to include something that was totally irrelevant to the design and the company.
Even the best design in the world doesn’t speak for itself to someone who walks in with a totally different concept in mind. You are going to have to explain to them the whys and the wherefores.
Your reasons for whatever you do need to be able to be clear and fully justified to convince your client what you did and the steps you took are correct and will work in their interests. At the same time, have an open mind and listen to what they have to say. Under no circumstances be argumentative. It neither pays nor will the client return if they have a bad experience with you. You want a happy satisfied client who sees things your way.
It is not impossible that they actually have a good idea so listen carefully and see if it can be incorporated into the design and be used to advantage. Never get defensive. Clear, concise descriptions of the where and why of the design will win more clients over than anything else.
At the end of the day the client is the one paying, and it is his or her website. A happy client is the best advert you can find.