There is a lot of content available which focusses on how to be more efficient: how to fly through your email, how to have the most smooth running meetings as possible, and so forth. However, I found that it is always more worthwhile to replace efficient with effective. You can be really efficient without actually accomplishing something, for example by running efficient meetings where the complete meeting shouldn’t be necessary in the first place.
By focussing on being effective, you’ll be making more impact. Efficiency can be fun, but does not automatically yield better results.