Often photography supports a hobby. I see many enthusiasts photographing trams in Blackpool, Lancashire. And any time a steam train runs up the Settle-Carlisle line, vantage points along the route are manned by train buffs with cameras. Many birdwatchers (birders in the modern parlance) "digiscope" i.e. photograph birds using a digital camera connected to their telescope.
But to move beyond these narrow confines is harder. Books, magazines, and internet photography forums are a good starting point for ideas for subjects, approaches and techniques. But one strategy that I have found useful is to name a subject to yourself and work at it until you get an image that satisfies you. The subject can be as prosaic as some vertical blinds. I took this as a starting point, and over a few days produced two shots (out of about thirty) that satisfied me. They are here and here. I've recently been trying to produce a shot using a local 1930s hall as the subject. On the face of it this building is photogenic, but it is big, painted cream, and is very long. Here's the first image that I am reasonably pleased with. A shaft of light had pierced the clouds and lit the dome and the nearby beach, whilst the sea behind was being hit by a squall. A ferry came into view, battling through the rain, and the contrast between the bright building and the dark ship seemed a possibility. A couple of gulls helped out with the composition. I used a long zoom at 300mm (35mm equivalence) and boosted the ISO to hand hold the camera in the strong wind. The post processing is minimal.
photograph & text (c) T. Boughen