Making the freelance/contractor jump. I'd love to hear your stories/advice!

Hi all!

Long story short, I'm a designer in the US with 10+ years of experience and a strong portfolio, and after my last couple positions have been a struggle with mismanagement/startup woes, I'm finally ready to take the leap and freelance full time (being my own boss has never been so appealing lol). Here's where I'm at - I'd love to hear any stories of you guys taking the leap, and I'm open to any advice or feedback on my situation!

• I plan to start in December - I have 3 solid customers interested in long-term contract work on board already, and figure I can supplement the rest of my income with smaller projects and one-offs. My network is pretty good.
• I'm trying to set up the business end of things, and I'm thinking an LLC might be best, but have also looked into s-corps and sole proprietorships. My biggest concern is that my husband makes significantly more than I do and, while I don't plan to get sued lol, I figure that an LLC can help protect our personal assets just in case something comes up. I don't mind paying more to register up front if it helps in an emergency down the line.
• We use an accountant for our personal taxes anyway so I'll probably end up going through them (or one of their recommendations) for business taxes as well - I know it can get complicated.
• I also plan to write up a solid boilerplate contract and have an attorney look it over before starting work with anyone.
• Other tips I plan to incorporate: collecting half up front for one-off projects, making sure to factor in 30% tax and sending that chunk of any payment straight to a separate account just in case, writing off expenses that can be considered business expenses (Adobe, wifi, etc etc).
• What do y'all think of business insurance - worth it? If so, what kind?

Any other advice from you seasoned professionals? I'm really excited about this and want to make sure I am in the best possible position before I start any contracts. I'm happy to answer any questions or give clarification as needed. Thanks so much, looking forward to hearing from you!