Ask for referrals. Talk to people you know, including but not limited to past clients and ask for referrals. This one simple thing alone can grow your business mulitple times over. The thing is that often times people may not even realize that you’re accepting new clients unless you’re vocal about it.
Let current clients know you’re open to helping, offer them a referral reward of a discount off their next invoice when they refer a friend. Chances are they’re already talking about you and your work for them, give them a reason to shout it from the rooftops.
Consider creating an ongoing referral reward system. Give clients and other referrers rewards for sending you new clients. Rewards can be financial or non-financial.