Pretty much the same.
A once over of reading all the way through, then re-read the summary, then generally each week the immediate part I will be working with in the upcoming session, jumping around to relevant parts.
I occasionally have gone in with just reading the beginning and going from there, I did that with the
1e Temple of Elemental Evil, reading about Homlette and Nulb and the Moathouse and the summary and running through the moat house but not having gone through all Temple parts when I ran it. Which turned out well when my group decided to skip town for Greyhawk after finishing the Moathouse instead of continuing on to the Temple proper.
Currently in my 6 module Iron Gods adventure path where I am in Module 3 I have only read the first three modules. I plan to read the 4th before running it, but I am going off the AP summaries and details in the first three to plan ahead on plot foreshadowing stuff. Having just started module 3 I am mostly focusing on the immediate stuff coming up which means the module plot summary, the town gazetteer, the likely town NPC interactions, and the town plot points.