When I first started freelancing as a university student, I was eager to do any website and would say yes to anything, regardless of my skill set or the time involved. It was just nice to know that someone needed me for a skilled task. Unfortunately, I quickly found myself working all the time, eating Ramen, and not getting anywhere in terms of paying off my college debt. Making things worse, word was getting out that I did free or cheap work. It was simply a bad way to do business.
Anyways, now ten years later, my world (and financial stability) requires the use of the answer "No." And here are ten questions I almost always answer "No" to:
1) Can you show me a mock-up to help us choose a designer/developer?
I fell for this a couple times as a young and naive developer. I made no money and spent lots of time on the work. Don't do unpaid work for the chance to be paid -- this wouldn't fly in any other industry, so why web design? The best case scenario (though rare) is that you get a job with a client who knows that you'll work for free when necessary. The more likely scenario is that they don't pay you and still use part of your stuff--and you waste your time.
2) Can you give us a discount rate or match this much cheaper freelancer?
There are a lot of companies out there that do not see web design as a service worth paying much for. These should not be your clients. In my early university years, I used to value "getting the job" so highly, I would take on an inordinate amount of work for the pay. You may be doing this company a favor, but on the flip side, you're hurting your own future. Nowadays, I give my hourly rate immediately, and it weeds out many potential clients. It's simple math really -- if doubling your rate loses half your client work, then you're still making as much in half the time. If you do excellent work, get paid for it – there will still be comparable firms charging double what you are.
3) Will you host my site?
Sure it seems like a good idea -- free recurring revenue right? Well, maybe... if you can first get them to pay, and then if you can justify making $10 a month for the endless phone support you'll have to give at all hours. Once the client thinks that you are responsible for their email and website functionality, you will get called all the time when their email shows the slightest wavering or their website 404s for any reason on their home computer. Don't do it...it's not worth it. Give them your recommended hosting company and let them sign up.
4) Can you copy this site?
This is an easy "No" from a moral standpoint, but there are other equally important reasons. First, if they're copying a site, they have shady ethics themselves and the chances of you getting paid on time and in the full amount are questionable. Second, doing this type of work reduces you to a simple execution machine, and although some of this work may pay the bills, why purposely pursue it? Third, if it's a true copy, the only benefit you may receive is payment - you really won't want to use it for a portfolio or example work, and furthermore, this type of client is one you do not want work from in the future.
5) Can I pay for my e-commerce site from my website sales?
I hate to be the pessimist, but when asked this, I want to tell them that they most likely won't be making the money they think they will--so they might as well ask me to do it for free. Yes, I know there are exceptions, so you should inquire further before judgement. But in the end, if they have a leigtimate plan in place, their plan should include the ability to pay you up front.
6) I have a great idea. Do you want to partner up and...?
Partnerships work when both parties can bring eqaul amounts to the enterprise. If the person adds little to the potential business outside of speaking an "idea," it's not really a partnership. Ideas are good, but there are a million of them out there, and it's the execution of a good idea that makes the money. In some cases, people believe that their idea is worth the same as you spending hundreds of hours to develop it -- such inequity does not end well.
7) Do you have an IM account I can contact you with?
I might give it out if it's to a person trust during an intensive project, but as a general policy, I tell clients that it's my general policy not to. This is my personal decision -- but I am far more effective for the client if I can focus large chunks of time to get them the best product possible. I still answer my emails very quickly, but on-the-spot messaging is not the best idea for a developer (unless you turn it off often). You just have to be careful not to become an on-call employee (unless your work agreement specifies).
8) Can I just pay the whole amount when it's done?
I typically require 50% up front (unless it's a huge job -- then 25-33%). I need that assurance that they have "bought in" on this project and on myself. Furthermore, I need to plan on the income to pay bills and eat. People who want to pay at the end are much more likely to back out after you've done lots of work.
9) Is there any way you could get this done on the weekend?
This is a general "No" but not all-inclusive. Because once they know that you helped them out one time, they may expect it in the future. Now you may choose to get extra done at night or on the weekends (I do all the time), but it's a slippery slope to start making promises about getting things done at night or on the weekends/vacation. Many freelancers charge night/weekend hours as well, so that might be a possible route to take.
10) Can I be sure you won't use this work in anything else?
This is a very sensitive subject because most clients misunderstand it (intellectual property is a tricky subject anyways). In my Terms and Conditions that I require all new clients to sign, I make sure they know that (1) their code has utilized code from other projects which I haven't charged them for, and (2) I will probably use code from their project on other projects, and (3) they own the code implementation of the project (finished website), but not the actual code pieces (login system, image uploader, etc.). They're not paying you to create code that they in turn have the rights to sell. (Now there may be exceptions where they want to resell the code or are willing to pay for exclusive rights--at which point you would develop from scratch and charge them accordingly.)
There are others I'm sure. Feel free to add your own and remember, it's the opportunities you avoid that will define your success just as much as the opportunities you take...
Note: I've gotten a good deal of traffic and comments on this post. Now that you've finished, keep this in mind: this post is by no means a systematic, all-inclusive look at the relationship of freelancers and clients. I often temper several of these depending on the situation because flexibility is necessary to success. Furthermore, I am also likely to break some of these for a client just because I love the client and/or project. However, such observations are moot in a post that is defining the general "No's" of freelancing. So don't think that this list is a holistic philosophy, but merely a guide that has helped me avoid some pitfalls I myself have fallen into. Best of luck!