Years ago, many freelancers have noticed these signs, they tend to ignore them or say something along the lines of, “They won’t be this way when we start working together.” However, the harsh reality of it is that they will be and that's almost a guarantee.
The Contract Revisionist
If you find yourself unable to come to terms after negotiating ten versions of your contract with your prospect, or if they keep asking for updated project plans before you’ve even signed an agreement, beware. They may show similar tendencies during the actual project, especially if the people you’re negotiating with are the same people on the project team. Wireframes, and design comps may be scrutinized to an extraordinary degree, and may also require the approval of multiple stakeholders. In rare cases, such scrutiny garners better results, but it more frequently results in watered-down, design-by-committee mediocrity.
If you encounter the never-ending contract revisionist:

• Ask yourself if your contract is bulletproof to begin with. Be sure to work with a lawyer on this, as he or she will consider aspects of your future working relationship that may have never crossed your mind. If your contract isn’t comprehensive, you’ll waste time getting it to a solid starting point.
• Make sure the contract you’re negotiating has plenty of wiggle room for revision work/iteration during the project, and protect that time during your negotiations: You’ll need it. Also, make sure you understand what might be causing the prospect to want to continuously revise the contract. Have they had a lousy experience with another vendor? If so, what led to that situation? Don’t be afraid to ask questions.

The Giant Project Team
One thing you need to make sure of is how many people will be involved in this project. That means, be sure to ask your prospect up front about how many people from their side will be part of the core project effort. If it’s a number greater than three, be careful. Large project teams, especially those in which everyone has equal input, often lead to unfruitful compromise and watered-down results especially from a designing and functionality point of view. They also tend to extend time lines, because receiving and digesting feedback from large groups can be a tedious process—especially since it can be delivered in contradictory fragments.
If you encounter the giant project team:

• Encourage your client to consider a working group of no more than three core decision makers two is the ideal number, and only involve a larger stakeholder group for the first presentation of major milestones. Invite the larger group to your first design presentation, not the third, when you're presenting finely honed work. If a high-profile stakeholder sees something late, you can count on reworking your design.
• Stress the fact that there is a direct correlation between the number of people associated with the project and the project cost. Involving more people is more expensive. People need to be paid for their time, and the energy project managers will spend orchestrating large groups and sifting through their feedback can add significant overhead.

The Vague Persona
Freelancers tend to stress the point but it often falls on deaf ears, as a freelancer it is your duty to have your prospects complete a project planning questionnaire before having any sort of meeting or initial wireframes presented. The questionnaire help us identify the prospect’s project goals and expectations and is also a reference tool if ideas and suggestions deviate from the overall structure. If questions are left unanswered or are only one or two words, it's a sign that the prospect may be hurried or disengaged, or that they don't fully comprehend what they’re looking for. On the other hand, if the answers are verbose, well constructed, and even conversational or witty, that’s a sign the prospect “gets it” and that the relationship could be very rewarding.
To avoid the vague persona:

• Consider asking your prospect to complete some sort of project questionnaire up front. If you don’t want to do that, be sure you ask them a lot of specific questions in a telephone or in-person conversation, not over e-mail. You can learn a lot about someone through conversations.
• Don’t settle for half-baked requirements. Break out the spreadsheet before you bid on the gig and start documenting exactly what the project requires. For instance, simply saying “We need to design a donation form” isn’t good enough. A donation form for what purpose? Accepting donations from whom? Supporting what forms of payment? Will it require payment processing? Form validation? Let them understand that you need the minor details to make your job as productive as possible.

The Prospect Who Is Always In A Hurry
A “typical” website redesign effort when executed thoughtfully and thoroughly, can take at least four to six months to complete. If doing a complete overhaul the time frame is usually greater than six months and this is without Content Management System (CMS) integration work.
This is the common issue many freelancers face. The situation: the prospect comes to you in November and says the site needs to be up and running in before the new year, be very careful about agreeing to design changes if you know that it is near impossible to complete in a two month time frame. Not only should that seem unreasonable, it also means you need to figure out why the timeline is so short.
Is the prospect simply trying to use up budget dollars?
Are they rushing to beat a competitor to market?
Are they being pushed by a high-level executive who is not familiar with the work the project requires? You'll need more time, especially if you already have other projects cooking.
If a prospect is in a rush:

• Be prepared to educate your prospect on your design methodology, and communicate that quick-hit decision making can often lead to significant (and expensive) rework down the road.
• If you want to take the gig, raise your rates. Your time will be consumed, so you need to make it worth your while.