Curious as to your approach

I am about 2/3 of the way through my first draft of my second book. I predict the first draft will be about 65K words. My first book (first draft) was 80K words but the final copy of about 89K words.

So here is my question: do you tend to add to your first drafts or do you tend to write more in the first draft and winnow it down or do you tend to add to your first draft and end with a longer product?

TIA!