Referral work, hands down, is the best. Sometimes slow, you never know when, but it's free. And it's the best paying work as well, chances are you're not being price shopped if it's a referral. If you have a large enough Client base referral work can account for 10-20% of your business. Also, if you're personable & likeable, call & ask Clients for business. Asking is free. Having a good 'findable' website helps a ton also. Tons of other methods also, what works for one may not work for another. That's why we're entrepreneurs right? We're creative & 'make it happen'. We're the people keeping this country going, creating jobs & spending money. My .02 cents.