The best way to grow your business, not the fastest, is to use your existing customer base. If you have regular customers, speak to them and find out what they like about your business and what can be improved. If they really like the work that you do tell them you are trying to grow your business and ask if they have anyone that might be interested in your service. Follow up and use your customer as a reference.
If your low on funds, treat your existing customers like gold and use their testimonials and leads to grow your business. It's easier and more effective than hiring a guy on zero salary to go out and sell something he doesnt care about.
In my business I have commission based sales agents, they do work if you treat them properly but nothing beats great WOM and great customer testimonials.