A misunderstood facet of gaining experience is that you have to have gotten paid in order to put the experience on a resume, to be competitive in the application process or to impress an employer in an interview...WRONG! The deal maker with experience as it relates to convincingly adding it to your armory of Dragon Slaying Stories (a la Liz Ryan) is your approach. Simply put--pursue every experience as if you're the boss and the buck stops with you. That is to say, let excellence be your credo, study up, and learn from your attempts.

So, what does that look like practically? Here are two common ways, and insigh into how they've served me well in my professional development efforts. Hopefully they will help you too:
Volunteerism- This is an underappreciated yet awesome way to gain valuable experience in an area where you're trying to build expertise, gain credibility, and establish a track record of success. Underappreciated because many people going through career changes are supporting families and/or still need to work where they are, so time can be very limited. Good things about volunteering include the great level of flexibility involved, and they fact that building experience doesn't really have to take that much time.
As a volunteer, you get to choose what you want to offer and doing your research will allow you to benefit organizations that can most use what you do well. Also, doing what you do well, and faitfully so, can put you in the front of the line for consideration should paid opportunities open up.
Personal anecdote: I signed up to volunteer for an organization, after research within areas of my personal interest, I appreciated the organization's mission and saw they had a need for an area that I was interested in, but didn't have very much experience with. Going through the proper channels that they outlined (i.e. volunteer application, orientation, etc.), I was able to present my enthusiasm as well as my prepared "pitch" to the organization's Volunteer Coordinator and Executive Director. This pitch including ideas for development/growth, researched best practices, and a communicated understanding of their current state with the area of interest. After six months of volunteering, doing good work, demonstrating results in the area, building good rapport with organization constituents, presenting new ideas, being open to assisting with other areas of need, etc., I was approached by the organization for a paid contract role! Not only that, the paid contract expanded over time as my expertise was developed and my professionalism continued to be displayed. I still work with the organization two years later!
Entrepreneurial Efforts-The Internet age makes almost anyone look like an expert nowadays. That's good and bad: good because you can get a Web page to advertise services in the area you're hoping to build toward and have a good presentation for those looking for what you offer. Bad because not everyone who has a Web page delivers quality (but good again, because you have an advantage if you do...). The goal is to be good at whatever you do, then "practice, research and more practice, training, practice, repeat." This represents a good model for success!
I had an individual mention to me in conversation that she was interested in breaking into recruiting after being in customer service in the healthcare arena for nearly a decade. My advice to her was to start finding people a job and be able to talk knowledgeably and in detail about your approach and impact. Is it really that simple? YES! The fact that you do it on your own can be more of a selling point due to the drive, initiative and resilience needed to be successful when you are your own primary resource.
Personal anecdote: My last year in graduate school as an intern, I was in a very different place in life than a traditional, straight-out-of-undergrad. graduate student. I was more interested in contracting or consulting than landing a full time role in the Career Development field, but if experience was required outside of my internships (and many did require that), I didn't have any! What to do?! I started a Facebook page that has developed along with my personal/professional brand. I, also, made as many opportunities to review resumes, offer career development advice and the like as I could--for free! I pursued the appropriate certifications and licensure in my field for added credibility. Lastly, when people I helped appreciated the service and products I provided, I asked them to share that (via LinkedIn recommendation, Facebook posts, survey feedback, etc.), and they told a friend, who told a friend, who told a friend. Three years later, I have a roster of near 60 clients, and a tested approach to my practice that I am sharing, in part, with you now.
The moral of the story is, experience can be what you make it. Some fields lend better to being able to manufacture your own opportunities than others, but that doesn't mean you can't or shouldn't try. These methods can be a good "hold over" until you find work in a different platform, like a full-time employee. They can develop into the kind of work you want to make for yourself as well, or can be additional roles you take on along with full-time work. The choice is yours and in this worldwide, competitive market it is always better to have choices.