Prepare for Your Worst:
Pre-mortems, pre-hindsight, and Murphyjitsu are all roughly the same mental technique; they consist of planning for things that can go wrong to tackle the planning fallacy. I think an additional frame that is perhaps implicit in the model, but might be helpful if made explicit is the assumption that your schedules should assume the worst-case scenario.
Not the worst-case scenario for the world, though. That would be a different thing altogether. I mean assuming the worst-case scenario of yourself.
Murphyjitsu suggests that we make plans by asking if they will actually work. On a good day, of course, things tend to go well— our attitude is fine, energy levels peak, and work gets done. It’s when we’re tired, bored, and lazy that workflow tends to ebb.
To that end, besides making idiot-proof plans, I think it could be useful to reframe plans that try to succeed, given that you are in a poor state. By that, I mean using past experience of your “bad days” as a benchmark for future performance. If the worst version of you is mopey, lazes around, then set counter-guards for that person, rather than making plans to require you to be awesome.
Make plans that work, in spite of your being lazy. Automation works well here; reframing tasks as Things I Do, rather than Things I Will Move Myself to Do could be useful.
In addition, using your actual past performance as your expectations for each day’s productivity also seems highly reasonable. You aren’t going to (in all likelihood) suddenly improve your work time by 3 additional hours. Given that, work towards doing at least as well as you did yesterday.
Our expectations often reach way farther than our capability. For me, I’ll try focusing on beating the suckiest version of myself first.