Sub-floor Preparation for Laminate Flooring

Hello Everyone!
This is my first post; however, I am a big fan of this website and have used the tips and recommendations from DIY.com for years.

My question is this:
What is the best way to level a sub-floor in preparation for laminate flooring installation?

I am going to float a "click and stick" 12mm +3mm pre-glued underlayment laminate flooring. (Kensington Manor 12mm Summer Retreat Teak Handscraped Laminate)

The sub-floor is 3/4" plywood nailed to 2x12 joists, spaced 16 inches. The sub-floor appears to be strong however along on the east and west walls, there is a dip in the floor that starts from 18 to 12 inches from the wall. The dip is anywhere between 1/4 - 3/8".

I was considering one of two approaches to level the floor. Either use self leveling compound near the walls where the floor dips and sand the floor smooth and flat, or to build up the low spots with 1/4" ply and lay down another level of 1/2" plywood over the entire floor to ensure it is totally flat and smooth.

I was wondering how the pro DIYers handle a situation like this without creating too much work for themselves while getting the job done right.

 

I would probably just use a quick curing floor patch and a 12 inch trowel. You can lay a 1/4" dowel or metal rod down near the wall and use it as a screed to get an even pull. If you are lazy, you can leave the dowel in the patch, or remove and fill after it sets up. Big orange has a product called Speed Finish by CBP that begins to harden in minutes. Don't mix too big of a batch or it will set up in the tub before you get it on the floor.

 

Thank you czizzi for the information.