I have up and down periods.  Several reasons, working on several kits at once and getting overwhelmed.  Work is a killer at times and just mentally tired to work on anything after a long day.  My other hobby astronomy sometimes takes me away from modeling. To help with several of these issues, I have decided to work on two builds at a time.  I also made Sunday afternoons as my model building time.  I just recently start doing this and it has helped me get more bench time. Plus, I am well rested by Sunday.