first, thank you so much, that means a lot ^^ and while i absolutely do not mind questions, i cannot promise my answers will be any good
to your question: i do use photo reference sometimes! here's an example of a piece i did vs the references i used:
i'll almost never use the exact same pose as a lighting reference; most of the time, an idea for a piece will come first, then i'll seek out references similar to what i have in my mind's eye to help figure out what elements i'm Not sure about (in this case, the colours and values to make an appealing overall composition)
with particularly unfamiliar angles and lighting on faces, i've sometimes used this neat tool
however, majority of the time, i'll usually either be drawing from knowledge i've collected (some of which you can see in this lil tag) or built up in the past (ie: using similar lighting techniques from piece to piece because if it ain't broke etc etc)