I am fairly good at time management and have found setting specific times and taking breaks really helps my productivity.
it does depend on what I am working on how I go about it but, a ( normal weekend just get to sew day) I allow myself 1/2 an hour to get organized, decide what I’m going to start with. Usually either time on a ufo or jumping into a specific project I’m in the midst of. When I am prepped and ready to start sewing I set a timer for 45 minutes. When the timer goes off I might finish a seam, iron something- whatever ( no more than 5 minutes) then I leave the room. Go get a drink, swap laundry from washer to dryer, get a snack, go to the bathroom, whatever- minimum 15 minute break. Then I reset the timer and get back at my project, or I set aside that ufo or whatever and work on something else. It is amazing how much I manage to accomplish doing it this way and the ( forced breaks) keep me from getting backaches, sore hands, shoulders, whatever. Even when I am at the longarm quilting for myself or a customer I set that timer & walk away ever 45 minutes.
You would need to decide what time works best for you between breaks 45 works great for me. Lunch time I stop, take an hour ( sometimes I am excited- really into my project) and itching to get back to it sooner- sometimes I decide I’ve done enough for a while & I stop. Timers are my friends.