I take it it’s not a general „how to stay motivated“ question applied to Mandarin.
Specifically, I use an app called cut & loss that runs on iOS, iPad, macOS (Mx) and I load natural audio, recorded from radio, Youtube, etc. into the app. The app generates a transcription from the audio, and every line can be listened to easily for however many repetitons you want. I focus on lines of text I like, I don't understand, or that feel like I should know. The app has a mode where you can repeat what you have heard, and transcribes it to any language as set, also Mandarin. I have also used the app for audio where I have the original text, and then compare the original text with the transcription when something does not seem to make sense, and "investigate".
What also works for me is to practice writing a few characters every day, one's I know, and ones I should know, based on if they appear in expressions, as words etc. that I want to know. I will then dive a little into the character, sometimes there is something to be discovered.
Try to find something you like, and that you feel like learning by heart, and repeatedly listen and watch, and look at the corresponding characters. Everyone likes to think of music, but one of my favorites is "A Record of a mortals journey to immortality", which you can get as a book, the first 30 or something episodes as a series (animated or with actors). If that type of story is not for you, find something that you do like.
Once you have a paragraph of text you like, that has some challenges for you (grammar, vocabulary, new character, rare character, uncommon thinking), stick with it for a while, copy it in handwriting, once, twice, every time you feel you should "do some Mandarin", but your battery level is low, have a pen and a Hanzi grid lying around. By the time you really get bored, you should have looked up every character.
When driving by myself, I tune into my favorite Chinese radio station, and listen to whatever they have: music, news, discussions). When going out jogging, I have an MP3 bone conduction player, which plays what I was looking at the last couple of days. Try to "hit your brain" from different angles, but on the same material, before you move on.
Depending on whether you use simplified or traditional, always look up the other side of the coin. No harm done, low effort, but when you are low on energy, something easy to keep you going.
I tend to think of these activities using the context of endurance training, so you need peaks, recovery periods, work towards certain "races", which could be "talking with Chinese, traveling somewhere where the language is used (not necessarily China or Taiwan!!), and have high effort and low effort activiites (effort depends on what feels easy for you, and what feels "argh"). "Argh" is useful, but keep it to once or twice per week max, so as not to spoil the fun or mentally scare you away.
What does not work for me, although it is generally recommended as good practice, is "establish a routine" (and everything that goes with it). But maybe it works for you. It is Tuesday, 10 am, I do some Chinese.
