There is this problem in web development life that a client comes to you and describe his project and you quote them based on their description, well it seemed pretty normal for sure but the wired thing appears when the client finds new stuff that he wants or desired to be placed on the website! so in this kind of case you will be bullied to apply those changes as you’ve quoted them! well after having a bad experience with some unprofessional client I’ve found that there are some steps to be taken to prevent this:
You need to get a full documentation of their desired work! you need to force them to provide you an exact example in case they want to involve their ideas, recommendations or styles.
If the customer is not sure what he wants and there are no sources available to provide to you, you need to make one scheme for them and provide it to them fully detailed about the features! the best way is to quote them based on pages and features that you include! in this case the client won’t have have the intention of asking for more features which are not included in the quotation!
one of the most hurting things for web designers is that they give the client a favor! sometimes client ask for something small! then we do it for them freely! which is not in the quotation! that sucks! it will lead them to ask for more! as its our duty to get them done!