@Indisputable
Honestly, I just gave myself 90 minutes to write and didn't do anything else until I had 6 full pages of info. I was like "oh, you're thirsty? write one more paragraph and you can have some water." lol, drastic times call for drastic measures. I finished my USC SOP first (it was due first), and it was a long one. After that, I based my other essays off of that one, because they all generally ask similar things. That's the best part about it. Once you have one, you'll have the others.
I wrote about a personal event to start, because from what I've read, you better grab that reader before they get bored and treat you like another random name and number on a page. I went into depth about why I was applying, my diverse background (I went to one of the most ethnically diverse universities in the country, so I talked about how that helped me develop into who I am today), how my work experience applies to social work even though I technically have no social work experience, a little bit of academia and why I switched from biochemistry to psychology in undergrad, and eventually, I talked about how I'm ready for this program and how I would work hard to utilize the information I'll receive to help other people. After all, that's why we're trying to become social workers, amiright?
so yeah, go off of that. show them you're a person; a person with strengths, a few faults, and a whole lot of ambition. They don't want perfection, they want you to be real and a little raw.
Good luck Hope I helped.