I don't have enough quality contacts to find these clients. And this kind of work is not common where I live so I don't have conferences to go... Do you have any suggestions?
I live in a similar place. Going remote is the solution, but again without a middle-man... Look for gigs on HN hiring/freelancer threads; weworkremotely.com; wfh.io; etc...
Even on upwork or similar sites, especially when the client is new to site, in case they provided contact info - contact them directly. Yes, and needless to mention - double (better triple) your rate.
Yep, and no need to mention the [race-to-the-bottom] site. Just check their website, contact info, maybe jobs/careers section, and contact anyway. And again, consider doubling/tripling your rate.
For short-term quick jobs - daily (better weekly) charging is preferable.
For long-term-like-regular-job - I prefer hourly billing, because I usually work part-time and with a hourly setup I have a freedom.