There is no absolute answer and unique tool/strategy in anything real estate. You need to learn how to use all the tools available to you (financing, insurance, management, etc.) and to understand how they fit together in your toolbox, as none will give you everything (e.g, insurance is required and it will cover you for many situations, but not always; asset protection (LLC) is litigation insurance and complements regular insurance, by minimizing the target and making it unappealing).
If you are a new investor, probably you will not have a lot of assets and/or equity to worry about (but even that is relative and subjective to each person tolerance to risk) so I would not worry about that till you pass that risk threshold (in my opinion 100K+ in equity, maybe 50K if you are really risk adverse) and you should be primarily concerned with finding good deals and growing your business first. Regardless, you need to implement insurance and proper management procedures, regardless of how many assets and equity you have. So, learn about that first - and a good point to start is a Nolo book (https://www.amazon.com/Every-Landlords-Property-Protection-Guide/dp/1413307000/) mentioned in the doc, it will explain about insurance, how to evaluate insurance, and then about property management, property code, proper leasing and all the way to LLC and hiring.
Think of it as levels of protection. Kinda like, one house, get good insurance and umbrella policy. Two houses, make sure you don't have holes in your property management. Three houses and 100K equity, start looking into strategic asset protection. Four houses, establish holding LLC and separate operations into a management LLC. Then couple it all with your estate planning and protection from outside attack.
You can do that from the begining, but might be overkill (since you'll have to learn to properly manage an LLC and there will be some costs associated). Of course, you'll be better protected, but will it be neccessary if you don't have much equity to protect?
Things change if you have a profession where you need to worry about asset protection from the beginning (like a doctor where you can get sued and lose your rentals too). Also if you are doing flipping, in which case I suggest you look into Series-LLC and you operate each flip in its own child-series (if not clear why, ask for more details).
I spent numerous hours researching from multiple sources the whole LLC question and asset protection matter and all the rabbit holes it opens. I gathered all my notes in a 50+ pages document touching on formation and maintenance of LLC and business structures, transferring assets, protection strategies, trusts, anonymity, insurance, levels of protection, etc. including when you should do it, how many properties per LLC, due on sale clause, selecting an attorney, fees, checklists and resource materials.
My notes file are primarily on asset protection, and primarily for buy&hold, but they touch on many other rabbit holes that opens from that (insurance, property management, DOS, transfers, etc.). It should save you many hours of research and hopefully clarify a lot of concepts (or at least I hope it does :>) as to why you want it and when and how.
Let me know if you are interested, and I can send them to you - just send a colleague request (to exchange files need to be colleagues) or your email. And I can give you a referral to a good asset protection lawyer too.