Who am I to tell you how to make your games? No one, that’s who! Have I released anything? Not really! This isn’t a guide for finishing a game, though there is a slight amount of overlap between “being productive and working on stuff” and “finishing a game”. Only a little bit. For finishing things, I recommend taking a look at Derek Yu’s writing on the matter. Solid advice you’ve probably been recommended before.
Don’t shoot for creative or inspired, go for discipline. It’s not very glamorous but it gets things done. Creativity and inspiration may come and go, but if you make something a regular habit and learn how to do it even when you don’t feel like it, then you’ll get more done. There’s nothing wrong with feeling inspired, and if you can, try to take inspiration from the smallest things! That drop running down a window? That can absolutely be a game mechanic or an art reference or something. Practice getting excited about things like a 5 year old.

Really, most of what I can say boils down to one thing: be optimistic about your work. Even if you aren’t an optimistic person, approaching your work (be it gam mak, writing, code, art, or whatever) from a positive standpoint will only improve it.
This doesn’t mean you should be uncritical of what you do - just remember that “perfect” is impossible and “good enough” is good enough. It can be hard to let go of insecurities or worrying about the quality of something, but personally I shoot for doing my best. If I’m working on something I’ll eventually show to others, I keep in mind what they might like (yes, I do in fact think of a Target Audience) but I never let it get in the way of what I like. It’s up to everyone else to decide if they like it or not. Thinking this way really does help you worry less about how good your work is.
Since pretty much all game-dev related work I do is in fact a hobby, this isn’t a privilege everyone has. If you aren’t being paid or working on a deadline, you have the freedom to take whatever approach or attitude you want.
A word of caution - I might say things like “do things your own way” or “you’re the one calling the shots”, but remember that this does not mean to act stubborn and bull-headed and ignore everything you’re told because “the creator knows best”. For getting things done, it may be effective, but if you’re rude and dismissive to folks you’ll have a hard time getting help with whatever it is you’re doing. And trust me, you will want the help or outside input eventually.
I may also say things like “stay positive”, but that’s hard! Again, it’s still important to be critical of what you do, but along with throwing out the need for perfection or finding ways to worry less about what other people think, at the end of the day if you’re not happy with something you’ve done, pause and ask yourself why that is. Once you know why, you can do something about it and hopefully make some progress. If you aren’t satisfied with your skill level, remember that you can only improve if you study and practice.
One thing that helps keep me focused is music. When I want to get pumped, I have a playlist for it - great for drawing, databasing, or working out! Sometimes I need something quieter, so there’s music for that, too. Combine with some relaxing noise generation and bam, I can get in The Zone.

But don’t think you can just keep going forever! Take breaks If you’re tired, work on something else if you’re sick of doing something. Especially when making a game, if you don’t feel like databasing… work on writing. Or resources. Or planning. No work is wasted work; even if you throw it out later you’ll have learned from the experience.
Most importantly: take care of yourself. I am assuming most of those reading this are human, and people have basic needs. Move, eat, shower, and sleep. If you work with a keyboard or tablet for long periods of time, make sure to stretch your wrists.

Your work is never going to be more important than your health, and when you push your health chances are your work will suffer for it.
“Taking care of yourself” extends beyond physical needs. Oftentimes when productivity comes up, people will tell you to make lists or hold yourself accountable or find ways to guilt yourself into working, and while I love my TODO list to death, I’ve never worked well on guilt. Again, it goes back to finding ways to be positive about what you’re doing. Be kind to yourself! If you feel you’re at your limit, take a break and come back. More than once I’ve had the painful experience of getting something done, hating every second of it, and then feeling incredibly bitter about the final product. To return to what I said earlier about hobbies: if this is a hobby, make sure it’s enjoyable. Not every second has to be sunshine and rainbows, but why make yourself miserable?

Despite all this talk of productivity, don’t get too wrapped up in keeping yourself busy. Go for having a sense of purpose, and be focused when you’re working. It’s totally fine to take breaks and stop to smell the roses. It’s more than fine, in fact - it’s important! After all, you can always work on your project tomorrow…
Right?
