Take English as an example. We spend a lot of time learning English every day. I don't think this is a good deal. You can refer to my practice here. We can recite words when we go to the toilet and listen to English when we brush our teeth and wash our faces. Usually on the bus and subway, you can also look at English, which is boring anyway. Chinese is not suitable for taking up our big plate of time. We can study in a small time, which is efficient and not so boring.
Then I suggest some types of crafts, and I can also study them in my spare time. It covers a wide range, such as weaving, baking, cooking, mixing wine, making desserts, making models and so on. Because my usual study and work make me feel very tired, I can choose to do something in my spare time to calm my mood and relieve stress, and at the same time I have mastered certain skills, killing two birds with one stone. This skill helps everyone to enjoy life and enhance personal happiness.
There are many tricks I haven't mentioned. I suggest you choose according to your personal interests or needs. Leisure time can not only relax your mood, but also improve yourself, which is of course the best.