My second time and money saver for laundry is keeping it all one color. All my lines are white or very very light in color. This allows me to do less loads in the end by using the following technique.
My kids both have their own rooms and laundry and of course hubby and I have a basket in our closet. All the dirty items from that person/ room go in the basket in their room including towels. Every three days or so that basket is emptied and divided between colors and lights / whites. If my linens were not white I would be running a nearly empty white load and a very full color load or possibly two loads of colors. Keeping the linens all white means more efficiency in water, electricity ad also time. I do not do a separate towel or sheet load.
There are some other benefits as well . I can bleach towels that are looking a little dingy and I don't have to worry what sheet go with what bed. Keep it simple. We do have colored duvet covers and comforters but those are thrown in to the colored wash on "light" laundry days so they do not create another load either.