They always say that a resume should fit on one page. Short of using four point type, though, how does a freelance squeeze all professional and freelancing experience onto one little piece of paper? One option is to create a freelancing resume and a professional resume, so that you can list your work experience or your list of clients with lots of room. Or, you can more clearly divide your existing resume, per Mediabistro Resume Revamper Alex Twersky's advice:
Generally speaking, freelancers who have a mix of freelance and full-time work experience will benefit from dividing their experience into 2 sections: a Freelance Experience section and a Professional Experience section. That way, they create minimal confusion in the flow of the document by not having freelance and staff experience intermixed. (The time frames and responsibilities of these two flavors of position tend to be disparate, so keeping them apart does indeed minimize any confusion). Additionally, by keeping freelance work separate from full-time work, the shorter durations and potpourri of assignments doesn't seem as scattershot (because it's the nature of the work) as it would if it were mixed in with the full-time job descriptions.