My suggestion is actually not to find interesting clients. My suggestion is to find high-paying clients and then to become your own 'interesting' client (aka, reduce your lifestyle cost to a point in which you're able to use this money to sustain months of self-directed work).

Nothing is perfect and I've no idea whether this particular idiosyncrasy would suit other people - I'm still undecided whether it's for me.

I would suggest looking in the mirror ;)

Let's be honest. Freelancers are not there to find "interesting clients". They are a temporary resource that enables a client to get a job done they under-resourced.

You have a choice as a freelancer 1) Become money focused. Earn as much as you can for as long as you can. 2) Become idea focused. Earn as much as you can until you have enough to bootstrap the idea. Rinse and repeat. 3) Become money focused but use your income to get the idea fleshed out using upwork.com

If you can get a few of you together it will be a better experience. Working at a co-location hub can be worth it.

Here's my advice after 7 years of freelancing: https://medium.com/@marknutter/advice-for-the-freelance-deve...

(sorry for the blogspam, I'd repost it here but it's long and I'm too lazy to paraphrase right now)

Pick a niche (with good characteristics) and make sure to be good at things in that niche. From there on, the client or employer will obviously pay you in the way that you want (freelance or employee). The work will also be maximally interesting. I personally get a fantastic rate doing pretty much what I like from my home office.

Echoing with the OP said. Figure out who your ideal client is: who they are, what projects they offer, how much they pay, etc. then go to where those ideal clients would hang out. Talk to them, understand them and figure out how you can relieve whatever business discomfort they’re facing.

This will take some time but you’ll eventually get a stream of the type of client that can support the lifestyle you want and want to work and refer you continuously.