There is a size of packing cube designated as "slim". They are approximately 14"L x 5"W x 3"H. I have discarded my packing cubes that are other sizes and now just use the "slim" ones. I like the way I can organize with them and they force me to pack light. My method is pretty straightforward, one cube for bottoms, one for tops, and one for underwear, socks, and PJs. I have found that if I roll my clothes tightly, they can't be compressed any further than they already are, so I don't get compression bags. I have found that larger packing cubes bulge out at the center and don't hold my clothes in tight rolls. Note that this is for my clothes only. I do have separate bags for electronics and toiletries.
Also, I repack my dirty clothes. I bring along grocery store produce bags and anything dirty gets re-rolled, placed in a produce bag, and packed into a packing cube beside its compatriots. I usually find a laundromat once a week and do my laundry all at once, this method isn't necessary for the daily sink washers.