Gathering together great minds to brainstorm the next groundbreaking ideas is not a new concept. Ptolemy I (Sotor) of ancient Alexandria created one of the first recorded think tanks by paying the great thinkers of his day to congregate and brainstorm -- an effort that attracted the likes of Heron and Archimedes. The National Center for Policy Analysis defines think tanks as "idea factories," but they're also businesses, albeit nonprofit. As with any start-up, practical financial and managerial considerations must balance creativity in order for the whole to thrive.

Define your think tank's purpose, focus and audience. For example, the U.S.-based Center for Strategic and International Studies says its purpose is "finding ways to sustain American prominence and prosperity" through new governmental policy. The audience it directly benefits is the U.S. government. The purpose of Canada's Fraser Institute is to research how financial markets and government policy affects individuals, with the goal of helping individuals attain greater health and prosperity. Your purpose will often come from a need you've identified -- the one that prompted you to start a think tank in the first place. Write down the problem or problems your think tank members will try to improve upon or solve. This is your purpose. Next, articulate whether the focus on how to improve or solve the problem will be through research or through policy. In other words, will you attack the problem through science and technology, or through government or organizational initiatives? Finally, identify your audience -- who are you improving solving the problem for?

Choose an individual to act as the think tank's executive director or principal. It's likely that for any problem you've identified as your think tank's purpose, there's already someone out there who has become an expert in it through experience. For example, Kenneth Roth, the executive director for Human Rights Watch as of 2014, had a long and venerated career in law, criminal prosecution and governmental investigation prior to assuming his position with HRW. He was also a veteran of multiple international investigations directly related to human rights. In other words, he was someone who legitimized HRW through his experience and reputation. Find the experts on your problem and approach them about becoming part of your think tank. Of those interested, select someone with a track record as a well-known and respected expert. As executive director, she will coordinate the efforts of all other participants by assigning tasks, keeping everyone on task, and overseeing the business details such as budgets and fundraising.

Establish your business structure. Remember that most think tanks need money and get it from donors and/or grants. Donors want their contributions to be tax deductible, which requires organizing as a nonprofit entity. Federal grants usually require this structure, too. The U.S. tax code states that a nonprofit must be organized as a corporation, a trust or association. The organization must have a federal Employee Identification Number regardless of whether it has actual employees. In addition, you must file the IRS form requesting approval as a nonprofit, provided on the IRS website, by the 27th of the month after formation. Most nonprofit structures require a board of directors and a hierarchy of internal management. You already have your executive director. Now, with the rest of your structure in place, you can show potential members and staffers you're serious about establishing the think tank and that it's worth their time to consider becoming involved.

Recruit members. Chances are you developed a good list of candidates when choosing your executive director. But make sure your potential member list is varied enough to cover all the traits necessary in a well-rounded think tank. You need not only experts in your problem, but also people familiar with project management, fundraising and research. For example, Human Rights Watch members include government policy specialists, attorneys, lobbyists and professors from all over the world. You may also want to recruit individuals who are already members of a think tank. Those who have experience working in a formal think tank environment can offer valuable guidance as your project gets off the ground.

Raise money. This includes more than just knocking on a few corporate doors and pitching the benefits of your think tank. It also includes applying for grant money. Both types of funding require much of the same information. Information packages requested by both potential donors and grant applications usually include a clear statement of purpose, focus and audience to demonstrate exactly what the think tank hopes to accomplish. Also, include biographies and resumes of your think tank leader and others who've signed on to participate to reassure donors that the think tank staff is qualified to address the tank's purpose and focus. Finally, provide financial information, including an operating budget, to show donors that your think tank is organized and financially feasible.