Schedules, climate, and other factors can limit our ability to maintain instrument currency in actual instrument conditions. The FAA allows us to maintain currency by using flight simulators and training deices without an instructor, but not all of us have access to an acceptable device. Besides, it is much more fun to fly an airplane than a desk.
The answer for many is a safety pilot. Regularly getting together with a buddy for some instrument work followed by a social post-flight debriefing can be rewarding. When VFR, we can include activities we rarely practice, such as partial panel or changing procedures mid-stream. We can work on proficiency, not just bare legal currency.
