Over nearly three decades in business, I’ve created mission statements that work well and others that have not. To craft a strong mission statement that's effective, follow these basic rules that I’ve learned along the way.

If you want to make a mission statement that you can actually remember, you have to make it personal. You must be personally invested in the process to create a mission statement that will really matter.

Other people may want you to include fancy words. Instead, use fifth-grade language that the average person can memorize in one minute. (And stop asking everybody else what they think. You know your business better than anyone else.)

1. Set the right boundaries for your mission statement. A mission statement helps you pin down on paper what you are going to achieve. For that reason, make sure yours has the right focus. Is your mission to serve the whole world with your fabulous barbecue sauce? That will be a massive undertaking.

You may be better off focusing on just the U.S. at first. Of course, you'll also have to guard against being too narrow. So don’t let your mission statement constrain your business too much. Just make sure that your mission statement is sensible -- but allows for growth.

2. Don’t expect too much from your mission statement. It’s not fair to ask that your mission statement to take on other roles; that’s when it becomes long-winded, mixed up and impossible to recall.

Your mission statement is not the same thing as your vision statement, unique value proposition or any other document that you think you need for your business.

Related: Five Reasons Why Your Mission Statement Probably Stinks

3. Refine your mission statement until it feels right. You might think that your mission statement is carved in stone, but it's not. So keep refining it until it feels right -- then leave it alone.

If you find yourself constantly wanting to tweak or add to it, remember that the mission statement is there to keep you in check.

Whenever you have a grand new plan, measure it against your mission statement and see if the idea fits. If not, you may be getting off track -- and your mission statement has done its job!

Related: Richard Branson on Crafting Your Mission Statement