It's all in the networking.
Most projects with sizable budgets already have vendors. Your best bet is to find projects that are on the brink of failure looking to jump ship to a new vendor. This is, fortunately for you and me, more common than you might imagine.
Ideally you can be brought onboard before the project begins, but software has huge sales cycles. Until a project is actively in progress, there is a strong chance it will never leave the planning stage. You can waste a lot of time courting clients for projects that never materialize.
My advice is to seek out projects that are in progress but need the help today, at least you can go from the first meeting to a sale in a reasonable time frame without getting strung along. At the same time, continue to network and establish relationships with clients who will be launching projects in the future. You need money today, and it can take years for clients to be ready to execute.