Employer Perspective
As a former hiring manager, reading a resume isn't about the positions held. I could care less about where you worked. It's about inferring a work ethic and ability to expand. If you grew in skills in an unrelated field, it's relevant to express growth. If you did something in a related field, how can I apply that to my need? Some things I would look for when reading a resume:
- Has this candidate used the skills I'm looking for?
- Has the individual in question been actively engaged in professional development?
- What is the growth rate of relevant skills?
- Is there an explanation for why the skills haven't grown at a rate I would expect?
- Given the previous questions, can I reasonably expect to train the candidate in the skills I need in a timely manner?
An employer-employee relationship often takes on the burden of training and professional development. You are looking to prove that you are worth their investment of time and money.
Client Perspective
When hiring freelancers I look for similar things:
- Does the contractor have a history of my task?
- Is there evidence of strong understanding in the area that I need assistance?
- How has the contractor solved problems similar to the problems solved by my task?
In a client-contractor relationship the expectation is that you can carry out the task at hand with little burden on the client. You want to highlight projects that are similar to the task being contracted. Primarily those that have been successful, but failed projects are acceptable as well if you can turn them in to lessons learned.
Contractor Perspective
As a freelancer, you can't afford to lose jobs due to inexperience.
Starting as a freelancer, you should use your resume as chronological reference to build your portfolio. In each past work experience, what have you done that can be applied to the type of work you are pursuing? Everything else is irrelevant.
You are responsible for sales and marketing of yourself. Why should they hire you? What makes you stand out?
I often take a client proposal and respond with a statement of work (SOW). With each skill expressed in my SOW, I look for at least one past project that highlights my capability of accomplishing the task.
Summary
If hiding previous work experience makes you unable to provide evidence that you are capable, then you can't afford to. If you can highlight your capability without it, then you can hide whatever you choose.
Stating that you've been freelancing for a period of time that you have nothing to show for will most likely have a negative impact. Leading to the assumption that you aren't very successful/efficient.