First, stop and pray. This is important because you want God's reasoning behind your homeschooling. It's unique to you and your children and there is no use in striving in our own strength. Striving in God's grace is the best way to homeschool and succeed!
Basically, we are going to decide on what we purpose to do through homeschooling. After praying, you will need to write down your values of homeschooling. Take out a pen and paper and start writing down words or phrases that capture your feelings about homeschooling. Think back on things you have said when people ask you why you homeschool.
Write down 10 things or so. Then, we are going to group them together. Ask yourself if you can combine your ideas in fewer words.
Here were my values not written in any certain order:
Respect for parents
Biblical world view
Strong study skills
Work hard to overcome difficulties in education
Take education serious
Parents are the main influences
Now see if you can begin arranging them in sentences. Think of a beginning line like, "We commit to..." or "We acknowledge God's call on our life to..." then begin filling in the rest. Feel free to make the mission statement as long as you like, but keep in mind it will be easier to remember if you keep it to a few sentences.
Here is ours:
"As long as the Lord allows, we commit to homeschool our children, first as a tool to develop strong Biblical character, sibling unity, and parental respect; second, to develop a love for learning, a habit of excelling, and a strong work ethic."
Pretty much all of my values are described within this paragraph whether specific or implied. This is something I can memorize and use as a metric to be certain each year that I am meeting our goals as parents through homeschooling.
Have you created your mission statement? I would love to hear it!