I use paintbrush to create the textures, so if there are major lines I make sure that they begin on left side at the same vertical position as the right side. This allows me to group them several tiles together so they are seemless.
I am attaching one of my more complicated textures. Complicated because it required matching major lines and colors on all four edges. It makes for a nice wall.
I tried the 256x256 texture...looks better...but not great. I still have a few tricks up my sleeve.....