I am sort of training towards my duathlon's for this year. I have improved so far. I don't have a plan as such as I don't need the pressure - just get out, run and cycle different routes, some with intervals, some with not.
I also have a few canicross events this year, so am hoping to improve on times- it is difficult to compare though, especially when each event is a different circuit etc.
I wish I had more time for exercise, however, I work full time and get 3 early shifts a week (615-215) which mean especially during the summer I can make more of the day and get more exercise in - rather than if I had my old office job and finished between 5-6pm.