Background processes in desktop applications are often overlooked in energy consumption studies, yet they represent continuous, automated workloads with significant cumulative impact. This paper introduces a reusable process for evaluating the energy behavior of such features at the level of operational design. The process works in three phases: 1) decomposing background functionality into core operations, 2) operational isolation, and 3) controlled measurements enabling comparative profiling. We instantiate the process in a case study of autosave implementations across three open-source Python-based text editors. Using 900 empirical software-based energy measurements, we identify key design factors affecting energy use, including save frequency, buffering strategy, and auxiliary logic such as change detection. We give four actionable recommendations for greener implementations of autosave features in Python to support sustainable software practices.