A specialty area for me, maybe this helps.
A few differentiations to work on first:
- Rest time vs. hobby time: This is a big one to learn to differentiate. You can indulge in your interests during both, but only the latter is typically going to let you really dig into things at a hobby-progress level. If you don't understand this you can drive yourself crazy and convince yourself that you can't focus, you're bored and so on, when in fact maybe it's laying-down-phone-scrolling time or loud-music time or mumble-karaoke time while you relax in the hammock.
- Ephemeral interest-focus vs. long-term interest focus: Your focus will come with different scopes attached. If you are experiencing the former, never fight it, that's usually a mistake. Especially if you focused on work a lot today. Call it ADHD if you want, but ride the waves, do what sounds interesting _not_ for your whole life, but for the next minute or two. Focus on switching as many times as your body/mind need until you start to settle into something. It's normal for focus to drift while a new context is found.
- Emotional involvement vs. routine-sustaining: Hobbies are passion-focused, and therefore can benefit from emotional judgment tools. Let yourself choose options based on feelings/emotions. Always rank them in a list in liked-most order, as this is a simple form of emotional expression. Over time you should end up with a master list which will be super useful. Emotions change and need attention. Don't force a routine to form unless you know for sure why that's necessary.
- Experimental you vs. fixed-concept you: Ask yourself "what would make this moment better?" Music, interactivity, whatever.
For example last week I needed to put in some time on the exercise bike but it felt so boring. So I made a quick handlebar mount for my scanner radio, installed super tux kart on my phone and watched a live PIP metal concert while I raced using the gyro controls. I was laughing after a while because my feet pedaled way faster when I was behind in the race. Listening to various ambulance, fire, police, ham radio, and air attack calls at the same time, there was something different to move the attention to the whole time.
- Showing up vs. developing skills: It's cool to find yourself doing something fun, and that naturally happens sometimes. But techies also usually benefit from hobbies that allow skill development over time. As you practice new hobbies, ask yourself what different levels of skill look like. Try to develop a mental picture of where you can take this in the medium term (risky to mess with the long term with this stuff, be careful), and what sounds interesting.
gl