1. Work with hand written bound, not looseleaf, notebooks as much as possible. Composition notebooks, 9.75 by 7.5 inches are available in the school supplies section of any grocery store. Record date of each day's work. You will do most of your work on scratch paper. But when you finally get it figured out, explain it in your notebook. Also include tips from co-workers, references to valuable books and articles, dates of important experiments, meetings and trips.
2. Stay grounded. Figure out things more than one way: voltage/energy, time domain/frequency domain, etc.
3. Do not wait to be asked to do something. You get your best assignments by figuring out what needs to be done and volunteering to do it.
4. Challenge yourself to work in different areas: analog, digital, system concept, etc.
5. Complex systems need more than specifications and descriptions. They need a decision document that explains why each subsystem was designed the way it was and not an alternative way. Any constraints on power consumed or heat produced should be noted to help assess the feasibility of replacing a subsystem with a different design later on.