Being productive although being tired

I asked a question on Twitter, and the amount of feedback and replies was overwhelming, and very valuable and very diverse. So for it to not be lost, I decided to blog about it.

This was the tweet:

Hey parents, asking for advice. My kid and I spend time until his bedtime at 8 pm. Then I would have time do read/learn/do stuff, but most days I'm too tired and end up with Netflix. How do you motivate to get stuff done in the evenings although feeling tired/unmotivated?

Let me give some more context about this, since I summarized and simplified to fit it all into one tweet:
I am divorced, and my 8 year old boy is with me every fortnight. For the weeks he is with his mother, I’m quite good at the „being productive“ front, I get enough stuff done. But since he is with me only „half of the time“, it’s very important for me to be with him, and spend time with him when he asks for it. If he’s busy with something on his own, I’m happy to let him be. But if he asks me to do an activity together, I only rarely deny.
Netflix was just an example everybody understands without further explanation. Could be as well reading a fantasy novel or scrolling through Twitter or whatever.

Following the condensed advice & tips I got from the replies:

It is ok to not always be productive all the time and it is ok to rest. You shouldn’t feel about that.
It is also ok to not spend 100% of your time with family and kids, but to also have some time for yourself, where you do what makes you happy, what you need.

Figure out what is your peak moment. Are you an early bird or a night owl? Adapt your schedule accordingly.

Try to change some things, for example use breaks at work to do some reading. Go to another place than home to be productive.
Although it may sound counterintuitive, do some sports to boost your energy level.

Figure out, if it’s inertia, or if you’re really too tired. Make sure that you have enough sleep to not feel tired.
To get over inertia, just start, just do. If you’re really too tired, it’s ok to rest.

Consider that there are different ways of „being productive“. Look for things that are more fun than Netflix, things you are passionate about.
Choose your activities according to that. If your brain is too tired for certain activities, watching conference talks on YouTube can be a good choice. Also, keep easy tasks for when you’re tired.

Write down and prioritize what you want to do and achieve, this way it’s easier to decide what to do.
For bigger tasks, it helps to break them down. This way you can see better, what progress you’ve made.

A lot of people mentioned habits, for example to reward good habits (allow yourself for an episode of Netflix, after you’ve worked for an hour.
You should build up habits, then you can rely on them, rather then on motivation.
To help you with that, chaining or habit stacking can help (The latter is explained in „Atomic Habits“ by James Clear).