I work full time, and the semester before I took the MCAT I took a class two evenings per week, volunteered at the hospital 4 hrs per week, had family life, church activities, etc. My advice:
1) Keep a schedule and stick to it. I had a calendar that I followed religiously. I usually only studied about one hour per day, but if the calendar said to study periodic motion, I made sure to get it done by the end of the day.
2) Always be ready to study, even if it's just for 10 minutes. My job doesn't have much down time, so I would study during lunch. I also studied while my husband was driving places...when we waited in the theater before our daughter's choir concert...while I brushed my teeth (reviewing formulas)!
When I gave exams to my students, I would study in my head while I watched them take their tests.
3) Be creative with your studying. When you've been working all day, just reading material won't work because you're too tired. So don't read any more than 30 minutes worth of material. After you've read, try to
do something with it...answer practice questions, write a brief summary of what you read, draw a picture or make a chart about the material...some interactive way to make sure you understand it and won't fall asleep.
Hope these ideas help! Good luck to you!