I was in your shoes for months doing research and looking for the right car. My humble advise would be to pull carfaxes, ask a lot of questions, get to know the previous owner (if possible). Something I do is take a look at the vehicle's tires. Mismatch tires are a red flag. If I see a brand new set of michelins on all for corners, that's usually an indication that the previous owner wasn't scared of spending money on the car and doing the proper maintenance. Look at the engine bay's condition, bushings, make sure no dashboard lights are on.
I will be more than glad to check the service history of the car if you provide me with the last seven digits of the VIN. Honestly, you are better off paying a little more and buying a car from somebody who babied it than getting "a great deal" on an average car and inheriting a bunch of headaches.
Best of luck!