It's not foolproof but that will certainly reduce your chances of working with someone that's not trustworthy. 

Umbrella policies are fool proof (unlike LLCs).  

It may not be foolproof, but taking a recommendation from another investor/homeowner that has worked with a specific lender would be a good place to start.In the future, try some local real estate meetup groups that meet in person.

At first this sounds bad, but LP has a superior warranty, is easier to work with, and is more fool proof on installation.

Checking their car is good but not foolproof.   

Not fool proof, but it's a good indicator. 

This method is not fool proof, as sometimes people just create new companies to continue their poor flips, but sometimes you do find a property to avoid.

So, while it cuts throgh alot of mustard in commercial financing, it's not fool proof, but I have used them and never needed them.As to the DIL, this was acceptable long ago, it was usually used in thin seller fianced deals along the lines of the contract for deed.

Are they fool proof - no, nothing is. 

Land trust has limited lawsuit protection, I realize it is never foolproof.