Probably the most important control provision is the board seats provision. Most investors will insist on being able to put at least one person (and often more than one person) on the company's board of directors. The board of directors controls most major decisions of the company - e.g., hiring and firing employees (including the CEO and other founders), agreeing to an acquisition, or raising another round of funding - so a seat on the board is hugely important in managing the company.

Every time you raise investment you'll probably have to give up at least one board seat to investors. Once investors control the majority of the board, the company's founders aren't in charge of the company anymore. This usually happens in the second or third financing. The founders should closely manage board seats to keep control of the company for as long as possible. Here are some tips for keeping control:

The bigger the better. Because investors will negotiate in terms of total number of seats (not percentage of the board), starting out with a bigger board can limit the investors' influence. One seat on a three-person board has a lot more sway than one seat on a five-person board. At some point, investors will push back on an overly large board - e.g., a company with a 10 person board is going to have a hard time getting investment - but having a reasonably-sized board can help limiting investor control over the company. Have a justification for the size of the board if it's more than three people, for example by identifying key executives or advisors that you want on the board.

The board should reflect the ownership of the company. Venture Hacks has the best discussion of this topic: //venturehacks.com/articles/board-structure. The basic idea is that the total number of board sheets should reflect the equity ownership of the company. If investors have 20% equity in the company, they should have 20% of the board seats. So, if you have a five member board, the founders should keep four, and the investor should get one.

Independent directors are great, but don't help you keep control. Some investors will insist on having "independent directors" on the board. In some circumstances, it's good to have a neutral party on the board to help steer the company. But, the independent director is not necessarily going to be founder friendly, and might be more aligned with the investors than the company. Be very careful in selecting the independent director, especially one recommended by investors, and make sure that you have some control over the selection process.

Require a new founder seat be created whenever a new investor seat is created. While investors might not agree, it makes sense to ask for this provision when investors are close to being in control of the board - e.g., where the board is split equally among founders and investors.

The guys at Venture Hacks recommend never giving investors more than the number of seats held by founders. While a 50/50 split is far from ideal-and investors can still take control in some situations-it's far better than an investor controlled board.