Sometimes you should present some slide decks that you didn’t create.
Perhaps someone created them for you, but in most cases, the slides are from some internal corporate repository.
I hate presenting slides that I didn’t customize to make them “mine”.
People can see if you don’t feel a connection with the content you’re presenting. So, what can you do in those cases?
1) Check if you can change the slides, or at least if you can change the order and hide some content.
2) If you can change the slides or the order, try to make the presentation “yours” without altering too much content.
3) If you can’t change the slides, check if you need to follow a “strict” script. You can still make the content “yours” by using the right words and the right stories.
If you have a fixed set of slides and a script to follow, try to do your best, at least by “feeling” the content you’re presenting, so your body language will seem “natural”.