Honestly I just be careful with the consistency. I try not to change back and forth too much. It changes as to create a more realistic feel, but it doesn’t change so much as to become a problem. It depends on the situation of which tense will be used. Though specifically dialogues will always end in present tense for instance. Paragraphs will be vary depending on the context, and appropriate wording. Though the context would still keep it present, but if it requires a past tense, then i’d make sure it fits correctly, or I try to do that is.
The way I choose to word certain scenes as well makes it tricky to keep consistent, but I try.
Protagonist deepest thoughts are explained with italics, and in first person. Certain characters as well will be in italics based on the scene at hand. Italics is usually an infliction of the voice, a cadence. So it can be used in several different ways. I am careful to express this. Specific inner thoughts are first person. While if a character can only hear the voice, it would be in third person.
I should also mention I would switch between 2nd and 3rd person tense at the end of a dialogue for two points. One to avoid redundancy, and two depending on the situation, this can be very impactful. I never use first unless it’s execution of action in the now. Instead of “said” I use “says” for instance.
I also choose to express thoughts in (). This is more or less action taking place in the now more specifically. It also serves not to confuse the thoughts of the protagonist, and flesh out other characters three dimensionally.
If there is one thing that makes me a bit angry is if people don’t read the author’s notes and then try to change the style of writing. I appreciate feedback based on grammar, punctuation, and so forth. Though some grammar as well is butchered intentionally to keep it realistic.
Now if it’s feedback on grammar, punctuation, reducing redundancy. etc, then that’s great, I welcome that. Since I can improve the writing, but if you try to change the style of writing, that’s an immediate barring.