I've never tried, but it's a little hard for me to imagine ever getting a client this way.
Then I would either talk to a worker directly if it looks like a decent opportunity. I'm not going to wave down a guy off the roof, but if he happens to be fiddling with something near his van and I naturally walk past, then sure.
If not, then I just call the number they have later. I'm not pitching them right away with "do you need any software developed?". All I do is ask them about their business. My goal here is to get a feel for how they are doing financially without directly asking.
Then I'll guide the call into casually offering them services that could help them grow. Sometimes it's a new website or setting up a landing page. There's honestly a TON of things that almost every business could benefit from and you can comfortably charge $2,000 to $20,000 for these things with monthly retainers on top. That's not even counting custom software gigs that come later.
But you can take these things so much further if you branch away from "just development skills" too.
I never talked to a food truck person yet but I bet there's lots of ways you could have turned that unfulfilling contract into something more interesting.
No business owner really cares about a site redesign. They just care about "how do I get more customers?". If you shift your focus from website themes, to delivering business value then suddenly a $1,000 wordpress site turns into a $1,000/monthly retainer because you're creating funnels and pipelines to drive business to his truck.
Next thing you know, he's paying you $25,000 for some crazy custom food truck software that helps automate his business which he has no problem paying because he trusts you and everything you've done for him in the past was amazing.
Fast forward 2 years from now and you have a food truck SAAS that 12,000 other food truck owners are paying $79/month for. Your whole life is changed from 1 conversation and you get to write code (it just took a little exploring to get to that point).
They're not paying you $1000 for a wordpress site, and they're never paying $1000 on retainer. The rest is also a total fantasy.
This is a misleading example because restaurants and food already operate on razor-thin margins; restaurant software is legendarily hard to break into and make money in.
Source: tried to start a "make websites for food trucks" business years and years ago, talked to hundreds of food truck owners, and learned that they're largely running food trucks because they like the hours, the freedom, the scale of the business. They can make decent cash without maintaining a space or even necessarily operating outside lunchtime. They don't really need to drive more business, and won't really anyway--their fortunes are tied to geography and the economy overall.
If you have an example from your own life, please use that instead of a fictitious one that is misleading and kinda wrong.
I can't force you into believing anything and that's fine but I don't think I need to defend myself here.
I have no agenda. I'm only bothering to share this stuff (along with the 100+ other posts on my blog) because I don't want to see other software developers go through the same mistakes I encountered along the way when freelancing for the last 20 years. I've been burned by marketplaces in the past.
Btw, what I described works (and has worked for me personally) with any of the niches I listed in my original comment and many more. No, I haven't created a super successful SAAS business from any of them but my idea wall has a dozen that could be made and would likely have some degree of success.
The problem is, I'd rather spend my limited time on creating software developer courses and building that up because unless you're passionate about what you do, you're very likely going to go no where in the long term and I'm not passionate about making SAAS apps related to industries I'm not personally involved with on a daily basis.
My point is that, especially if you're offering courses or trying to teach people, stick to what you know about from experience, not what you imagine might work based on an extrapolation from first principles.
That thinking, that it works in theory and that's enough to sell, is dangerous, because it lets people go a long way down the wrong path, just trying to think things through.
OR, if that's not your intent, don't make up fake examples that are obvious nonsense to anyone who's tried it.
Continue working on freelancer.com and I'll continue helping businesses grow while living my dream as a freelancer.
For reference I have been doing what I wrote for 2 decades and it certainly works. Good luck!
And they (we) have a tendency to think, "here is a system that I have derived from first principles, and now I can apply it" ... which is, frustratingly, not how the world typically works.
No plan survives contact with the customer, but the kind of confidence that guy writes with can be dangerous because it can lead people down a long wrong path.
Watch the Great Food Truck race. Those are the margin. Those are the $$ amounts. It is hand to mouth.
The tricky part for freelancers doing this is that most developers don't have that sales type mentality. It has worked for me in the past but it's definitely something I've recognized at not being good at