Time-Line Your Day
Lay your entire day out the night before. This includes lunch, your graphic design project(s), picking up the kids from school, your graphic design project, dinner, family time, your graphic design project(s). Design your day!
These are goals that you are working towards and if you go over the hour, that’s OK, just keep working. Forever more, do not punish yourself.
I have both - a home office and a studio downtown. I work mostly at the home studio when doing writing and designing. Downtown is where I shoot and do some editing. Planning my day on a sheet of paper (yeah, paper on a clipboard) helps me keep productive.