A good, generic strategy is to come up with some goals, then come up with some measurable criteria to judge success or failure for each goal. This helps you recognize problems, mistakes and inadequate plans (plans that somewhat work but not enough to reach the goal measurements).
Measurable criteria help with dishonesty and bias. Instead of moving the goalposts when you get there, or rationalizing how great you did, you clearly know in advance what the goal is (and write the goal and criteria down, often where other people can see it).
If your goal is "learn some stuff about physics" then it's hard to judge how well you're doing. It's pretty easy to fool yourself into thinking you succeeded when you didn't learn much. Or you could learn a fair amount but miss an opportunity to learn way more.
If you have measurable criteria, you can check whether you succeed at them. E.g.:
- spend 3 hours a week minimum on learning physics; miss zero weeks this year. (only solo learning counts for this time, not talking with people)
- post at least one physics question per week on stack exchange (at least 40 weeks this year).
- fully read the following physics books this year: X, Y, Z.
- do all practice problems in books X and W this year.
- at end of year, be able to get passing scores on the physics tests i found online (A, B and C).
This criteria aren't perfect. They don't measure everything I care about regarding my goal. I could succeed at these criteria and still have missed some opportunities.
But they have major advantages. They give me some clear guidelines. It'll be hard to lie to myself that I did one of these criteria when I didn't. They're easy to evaluate as either success or failure. Did I do it or not? I'm realistically going to be able to give a clear, correct answer, even if I'm pretty dumb and biased.
(What if I stop keeping track of time spent on physics, so I can't say if I succeeded? What if I don't keep track of what sections of what books I've read? You can take it as implied that that's a failure. Part of the goal is to keep track. Or you could write it into the goals that keeping track is a requirement.)
It's hard to measure everything we care about, and some goals are harder to make relevant measurements for than others. But measurements are useful and we can often get some benefit from them.
FYI you can find ideas similar to the above in various business management ideas. Regarding business management in general, I favor Theory of Constraints, from Eli Goldratt, who wrote a book actually titled The Goal.