What do you do if after talking to a client, you find out they aren't the right fit... either their business morally doesn't align with you, there are red flags, or you aren't as interested? My gut is telling me this might happen with a future call with a potential client. Not sure why, but I hate writing those emails that we aren't a good fit. It seems like a slap in the face somehow!
The fact you recognize when to say no to clients who aren't the right fit already puts you in a really good position, so kudos!
It's great to be sensitive to how the client may feel -- being able to empathize is a good thing -- but when you run a business, it's absolutely appropriate to consider your needs first. And when you work with people who aren't the right fit for you, no matter what the reason, you're taking precious time off your own plate that could be spent pursuing opportunities and clients who are.
If circumstances allow for it, I'd suggest to go ahead with the call, and if your feelings are validated, just be straightforward but polite. A bruised ego is certainly a possibility, but in my experience, people generally appreciate when you're not wasting their time. I know this kind of result might vary depending on your industry and type of client -- for example, I can see this being a more difficult conversation in say, the wedding industry, where it could be trickier to communicate kind of feeling with a bride vs. an industry like mine when I work primarily with business owners -- but ultimately they will be better served working with someone who is the better fit , even if they can't appreciate the step you're taking to get them there. How much detail you want to provide in the why is up to you, but a kindly worded note of appreciation for their consideration and some direction to help find a better fit for their project has always been sufficient for me. Your mileage, naturally, will vary.
I wanted to add a quick note at the end here: I acknowledge that not everyone has the luxury of being choosy, but I would still caution against the urge to ignore red flags or taking on a project that is clearly a mismatch for your skills, approach, or values. If you still find yourself considering it for more pragmatic reasons (say, to pay the bills that month), I would encourage you to:
2. Never underestimate the time and resources you'll be putting into a high maintenance / mismatched client -- more likely than not, you won't be making near enough on the work to justify the effort put in. If you choose to pursue it, make sure you can be properly compensated for your work.
Ultimately, you know yourself and your potential clients better than I do. With time and experience, you'll build up enough of those instincts to recognize when it's best to leave business at the door.