Hello BP Flippers!

I have heard several times on the podcast, that when looking at your first flip, people recommend cosmetic flips.  My question is, what kinds of things should I look to improve, and how do you stop yourself from going further?

In my area, there are lots of homes built in the 1900-1960's.  Homes are clearly outdated and need things taken care of like lead paint, new windows, paint, etc.  One example that I am thinking of is you go into a house and say, "I am going to update the kitchen since it is small and outdated."  How do you prevent yourself from going through and rewiring the entire house when you only wanted to update the kitchen?  I don't want to "Put lipstick on a pig" but I want to do a nice job.  Where do you draw the line between those two when you are doing a cosmetic flip?