Best Way to Cashflow GC Business; Other than Doorknocking?

[Account Closed]

Other than door-to-door hangers, having kids run around a neighborhood, or begging for contracts from past colleagues; what is the best way to market an established, design-build/CM/general contracting business that took a few year hiatus..?  

Social Media Marketing seems to create phishi'y leads; linkedin is too (TBNT), Craigslist now charges...  

$1 Billion+ in construction projects delivered, and years later I am rusty about how to source new construction and general contracting leads..  What new strategies exist for entrepreneurs entering the market as self-employed after extensive success and career achievements?