I have Rick's 20" rollaboard that zips out to become larger and needs to be checked if unzips to the larger size. I also have Rick's packing cubes but I find the larger one to be too big to ever use. I like the 2 small sized ones. Often I stuff my undies into my extra pair of shoes when I pack, but when I arrive, I use an empty packing cube as my "underwear drawer", which stays in a shelf, which I prefer over putting things in drawers. I am less likely to forget items if they are on a shelf or in a closer. I only pack 2 cubes in my carryon, and have never used the larger cube.
I did purchase another small-ish packing cube, Eagle Creek brand, I think, and use it sometimes. I also use larger ziplock bags to assist in packing; i like the type that have a wider bottom, they are great. I roll my clothes and some clothing will not fit well in a packing cubes, so things like pants are tucked in around the packing cubes.
I also use Travel Fashion Girl's packing lists. She has a 12 item list and a 15 item packing list that I use as a guide. it takes a lot of self control, but I was able to keep to 15 pieces of clothing.
I also use a personal sized carryon in addition to my rollaboard. I just cannot keep to the one rollaboard, as others have done, I put the things I need while in flight under the seat and the rollaboard up above. One the trip home, I expand the bag and check it. Then I use a thin bag that packs flat as a second carryon; sometimes I have put my dirty clothes in plastic bags in that extra carryon, it works for me if I have purchased some things while away.
I also have a packing list that I use to create each new trips' list; that works for me. If I move sites often in my trip, I use it to help me remember to get everything re-packed.
That is what works for me.