Tips for decorating with a toddler?

My son is just about 15 months old, this will be the first Christmas that he’s mobile and obviously into everything. How do you set up a Christmas tree when you have a toddler 😅 unfortunately there’s no where we can put it that he can’t get to it, I was thinking about maybe trying to put a gate up around the tree but I’m not sure how it would work. I think once it’s up for a while he may just lose Interest in it like he does other things. Does anyone have any advice though? Thanks in advance!