If you are writing in the first person, you can't avoid using "I" all the time. However, a good strategy is to avoid putting "I" at the beginning of every sentence. Using these sentence starters can help you to make the sentences seem more varied. You can also use phrases such as:
"As a person with an education background... "
"Giving her the grade she deserved..."
Although they can be somewhat awkward, you can also use phrases like: "this writer." "people like myself who are born in California, " or "in my opinion" to indicate yourself.