I looked through the related questions, but I didn't find any concrete advice.
I understand that it's OK to do so. I'm not sure how common it is, but I'm a beginner writer and want to keep things as simple as possible. I can pick up that fancy stuff later.
To illustrate the problem, I'll use the following example, where first-person POV narration has present tense sandwiched between past tens in a single paragraph.
I wound through the corridors toward the center of Down 15. None of the elevators were nearby, so I bounded up the stairs three at a time. Stairwells in the core are just like stairwells on Earth—short little twenty-one-centimeter-high steps. It makes the tourists more comfortable. In areas that don’t get tourists, stairs are each a half meter high. That’s lunar gravity for you. Anyway, I hopped up the tourist stairs until I reached ground level. Walking up fifteen floors of stairwell probably sounds horrible, but it’s not that big a deal here. I wasn’t even winded.
From "Artemis" by Andy Weir
When I go through my texts, I see that I'm doing the same. I'm writing in first-person POV, past tense, but when it comes to descriptions (little info dumps) and the narrator's thoughts (comments) I often switch to present tense (without thinking).
The problem lies in the word "often". I don't do it consistently. Also when I find a spot like that I start to think can I really do that? If in the above example the Moon was blown up by the end of the story, would it still make sense to talk about the stairwells in the present tense? It's just too complicated to deal with all these logical traps. I want to keep it simple.
I can't just search for present tense (such as "are") in the word processor. As we use the present tense in the dialogues.
Is a good copy editor the only option?
Or is there maybe some mind trick that one can use? Like maybe one needs to pretend and always keep in mind that a story is told by a person who is at his/her death bed, the events happened years ago, and the storyteller doesn't know anything about current state of affairs (what happened to all these people and places). Can a certain mindset break a habit?
Any other ideas?