I am a relatively new investor and looking for mainly buy and hold, cash-flowing properties. With that being said, what are some methods and calculations that a veteran investor would use to determine if a property is worth the time and money?

PLEASE SHARE ANY INFORMATION YOU MAY HAVE, WHAT WON'T HELP ME MAY HELP SOMEONE ELSE

I need to own for all-in cost of 75% of it's comps 

I try to buy something so ugly that people's fear of it will create disproportionate margin against what the repairs cost

Is the area in actual population growth or is it stagnant? This tells me how much I need to buy on appreciation versus cashflow. 

I want to buy at a higher price::rent ratio than the zip code average.

@Alexander Felice This is invaluable information, I appreciate you sharing! Will definitely take it all into consideration.

Your definition of success will drive most of the metrics you use to measure it.