I do not like to randomly change tense or perspective, and prefer to write everything in past tense from some variation of third person. 

And in case anyone didn't know, there are (at least) three ways to handle third person. You've got omniscient, where the narrative knows everything that's going on, and limited, which tells the story primarily from a character's perspective or the narrator's perspective. I tend to prefer limited, and which type of limited depends on the character. 

Tense just sounds better when it's past tense. But you're never writing exclusively in one tense because there will be times you need to explain when something is happening at the same time or how something correlates to things that have happened.