I'm having trouble understanding how people assess scientific papers as I'm a layman in reading them and statistics overall. 

My general (and probably too simplistic) heuristics are:

"Is the p value significant?"

"Is there a large sample size? Or small?"

"Is the population studied generalizable?" 

When I read the comments in the post I hyperlinked, it doesn't seem to click for me. I need more detailed examples. Perhaps someone taking a deep dive into one specific study and picking it apart, from the introduction to methods to discussion and ending at the conclusion. Mentioning what they did right, what they did wrong, etc. 

Does anyone know of any I could reference? I'm specifically reading positive psychology papers if that helps.