I'm also really bad at keeping a schedule, but its something I have been trying to work on more and more over the past couple of years. My oldest goes to preschool MWF afternoons so that is one thing that stays the same. During the winter months we are pretty much homebound except for drop off and pick up from preschool. We only have one car and its hard to take them both out anyway. We tend to run errands and do outings on the weekends when dh is home from work and can go with us.
One thing I have managed to do is have a morning routine, and so now I'm working on an afternoon and evening routine as well. In the mornings:
-DS2 nurses in bed and then we get up go downstairs, go potty, change R's diaper
-Get the boys and myself each a drink, then 30min. video/computer time so that I can wake up
-Then I make breakfast, we all eat and take our vitamins
-I then clean up from breakfast, and will start a load of dishes if needed.
-Go downstairs and start a load of laundry.
-Get boys dressed, wash faces, brush teeth and read stories
-Then I take a shower, get dressed, etc.
-Do a quick pick up of the main living areas
-Switch laundry and play w/ boys
That's all I've managed so far but it is a start. It probably wouldn't work for anyone who doesn't like a lazy start to the day.
I have also been trying to have lunch and R's nap at around the same time each afternoon but it can vary. I'm also trying to get dh and the boys themselves more involved with our evening routines of dinner, picking up, baths, etc.