While this is the similar to other posts..... I would say you need to get your name out there. To anyone you can (end users, other engineers etc). I have received referrals on projects that other engineers a) didn't want b) were too busy to do.
There are other posts in other forums about engineering consortiums. Groups of people who work out of their house and pool resources when necessary.
I do work at ever level. End users, architects, contractors, fabricators, manufacturers etc, other engineers. Most of these are either former co-workers or former clients. It has just expanded from there through WOM.
There is no one thing that you are going to do that is going to get you the work you are looking for.... it is going to be the 1,000 little things that you are going to do that will get you work.