I would be interested to know how many designers compose a mock site for the client before the contract even laid out and signed? What process do you follow? At what point is good to tell the client that the work will not start until you sign the contract.
First a warm welcome to WmW. You found a very good place.
Personally, I would not recommend anyone to start a part of the work before the contract is finalised. Not even a rough draght.
A site must be built whith all conponents approved. When some customers see us delivering HTML documents too fast, they are on the impression that building a site is a simple task. You can then fall in some kind of infinite loop where no one will be satisfied.
Some detailed plan including, texts, deadlines and budget must be approved first, then comes art skeches you can both discuss.
It is only my opinion. If you use the "site search" feature on top you can find many good treads.
Currently, the only time I will build and present a mock-up of a site is if I have had several discussions with the prospect. The prospect has an existing successfull business that they are promoting. They are not in the "I hope a web site will save my business" mode. And if I can present the web site in person. Generally, I will only present a graphic file (I.E. Photoshop file) on my laptop.
In the early phases of my business I would build sites to present to prospects. At that time it sold. Later on it became a terrible waste of time and the prospects perceived that I was desperate for business.
IMHO Build a portfolio even if it is demo pages and refer a prospect to those to show your skills.
I have read some books on this as well as researched it online but you guys have cleared it for me.
I completely agree with the point you about if the client sees how fast you can come up with a comp than why is going to take another two months- This could create complications and a misunderstanding the in the process.