I am constantly trying to find more efficient ways to pack.
I saw a video of someone who switched from medium sized packing cubes to small ones. I gave it a try.
I'm using mostly Thule compression cubes. What a difference. I have so much more space than before. Not that I'm going to take more but my bag is not as fully packed.
Each cube holds two shirts. One cube socks and undies. Another two sweaters. (I leave today for a trip that will include very cold weather.) My pants (trousers for our British friends) are laid flat in the bag and not in a cube.
I also now stack them vertically rather than flat when looking at the open bag.
This may not work with bags that have two even sides. You'll have to try and let us know.
If this turns out to be a bad idea while traveling, I'll let you know.