I'm lucky in that my main subject matter is the temperate rainforest of BC's north coast. I've walked some trails hundreds of times, but will always take great meandering archs off of the trails into parts of the forest I've never seen before. Everything is jammed tight with growth, and if you move 20 feet in any direction the compositions completely change. The trick is finding the 'keeper' compositions in a maddeningly infinite array of possibilities.
Different people have different strengths, and mine is to photograph that which I understand the most.