Well for me it is daunting but also a fun challenge. I am experienced at writing but not a professional. My years in public and academic work settings required me to write, but even that was not always joyful (many times technical), rather than story telling.
So the joy of genealogy and family history has made me see through this venture, eventually.
In the meantime here are some general items to think about when you decide to write your own history. Who do you write for? Yourself or a family audience. I would lean for a general audience. However at first draft writing from the within to tell a story is enriching. Format of writing: is it going to be a book?, an article?, or something else?
The scope is very important. Starting can be daunting because you have parents, grandparents, uncles, aunts, generations of research gathered. All I am saying is to outline these as sections and start with most current, then working your way back. Themes will also arrive through the practice of writing on the generation and time you focus on.
Lastly focus on setting deadlines to help you accomplish your writing. Though I am not done with any of my family history, I did set a goal for having most of one side done for a family reunion. Use events to your advantage.
Cheers and best of continued success in your Family History.