Doubling up on deposits or requiring larger deposits might weed out some of the riskier tenants upfront, though it's not always a foolproof solution, especially in markets where affordable housing is tight.Regarding your point about double security deposits, you're absolutely right-this can be an effective strategy.

Nothing is absolute or fool proof and there is risk in any investment but the GP should take their time to try and analyze the risk as best as possible so it is minimized.

Changing your mind " Is a foolproof legal defense .

Even this isn’t foolproof but it helps.

The description kept mentioning a fool proof system, and then the pricing for it was exorbitant.

It's not fool-proof of course but after years of doing this that's my best recommendation on how to find the best of anything real estate investor related. 

I've heard many times that moving NW from Logan Square into Avondale and Portage Park is a pretty foolproof approach.

And while not foolproof, it should help limit some of the pain that goes into finding someone new. 

However, these walk throughs are fool-proof, it's just a measure to check in on the property.

Not foolproof, but a very good way to start.