Research by Anders Ericsson on deliberate practice shows that the answer to this question is about being stretched just beyond your comfort zone. To clarify, it's about constantly attempting what you can't quite do. Great performance is built on five simple, but sometimes painful and deliberate steps:
--Stretch into a new challenge, setting, skill or competency. (You're building on current competencies.)
--Focus your efforts to overcome the new challenge.
--Get plenty of feedback about the results. Often you can get feedback by prepping partners or others to observe your actions.
--Adjust and resolve the mistakes you made.
--Recycle and keep stretching.
What you're doing is adding small chunks of ability, piece by piece, making certain that you focus on those small wins, and integrating each successful chunk into your tool kit. Recycle, recycle, recycle. You succeed by the multiplier effect. It's like making a small monthly deposit into a retirement fund. The first few years it's very small, but as you keep adding each month, you'll find it to be a very large fund for your retirement.
Follow exactly the same model in all skill development, technical or behavioral.
This past week I worked with three senior architects on developing client relationship skills. We've chunked the issues. The research, for example, shows that the first thing clients buy are not products or services, but warmth and competency. You can read further information on my blog, nice guys: does it pay?. As the blog states, you can't overestimate the importance of warmth (liking) and competency in building long term client relationships. However, as the research shows, warmth is always the first deciding factor for a client relationship, not competency.
Warmth is displayed through a number of specific skills or chunks: language tone, emotional tone, facial expression, nonverbal space management and listening tone. These are all actions, but they're far too difficult in one fell swoop. Furthermore, they're actions that you should see so that you can mimic them. In our session, each associate picked the one action they felt most comfortable with and set out to observe that action in others. After a number of observations, they committed to trying on the skill for themself.
FYI: Learning new behaviors, whether project management, negotiation or warmth often poses emotional difficulty. People feel weird trying on a new behavior. It doesn't feel natural or comfortable. My rule has a terrific basis in research: Fake it and you'll make it. Again, it's weird, but it's exactly the same process most of us have to go through to add new behavioral skills.
It's that constant addition of chunks, small though it seems, that will eventually make you into a great performer. This same straight-forward process makes it possible to learn complex technologies or difficult behaviors. It works with chunking, feedback, and the multiplier effect.