In order to keep my representation of perspective and detail in tact, I have been practicing with timed sketches. Giving myself 60 seconds to sometimes 10 seconds to not only find the subject on the spot but draw it too. I find the outcome never fails to surprise me. Obviously the drawings as a whole are not works of art, but I find there are sections within the drawings that I love, yet could not possibly recreate because of the speed, spontaneity and completely momentary situation.
This makes for good practice and sometimes, good inspiration. One sketch can lead to a tangent.