I've always liked to make gadgets and gizmos that fill some need ... some useful (or not so useful) function. It started with the simple things that many kids make - slingshots, a simple bow and arrow, a toy boat. Occasionally more involved items such as a canoe and a dune buggy became trophies to add to my accomplishments.
Simple things appeal to me more than more costly homemade items. A project with a small amount of time invested seems more like entertainment. Projects that use up more time and money make me think I would be better off doing something else.
So now when I don't feel motivated to do more practical things I often turn to an idea about some device or other that I've wanted to try making but never got around to.
I can recall many such improvised devices that gave me much needed diversion from the grind of more practical endeavors. Time spent earnestly involved in the creation of something designed and made with ones own ingenuity can be quite enjoyable. Each project gives me something to be proud of and more evidence that I am capable of more than tediously repeating over and over what I have done too many times before.
Ideas for things to make come from many places. Most often the idea comes from some need. I do a lot of keying of text using a computer keyboard. I tend to keep the room temperature a bit cool, cool enough that my hands become uncomfortable. I ended up rigging a length of electrical heating tape wound in a large coil-shape to surround the keyboard. Tying the heat tape to a large piece of cardboard keeps it in place. It does a nice job of keeping my hands warm. I can leave the room temperature set where I want it. As far as I know, you can't buy anything like that.
It is fun and satisfying to conjure up and build simple devices. Those created items command more appreciation than more casually acquired, purchased items. And it feels good proving that imagination and ingenuity can make life better. Having witnessed first-hand the process of invention, we wonder what other things we can achieve.