Since the last startcraft post seemed to be popular. Here's a quick tip my friend only told me about the other day.
Ever notice how some players have much higher actions per minute than you? Even though you've built just as much as them...
Turns out its not necessarily how many actions you completed in that one minute but instead if you spam your hotkeys and place 5 pylons in 10 seconds and nothing else for that minute. You will have a hugely higher APM than if you built 5 pylons over 50 seconds and did nothing else for the minute.
In other words, quickly issue a stream of commands over a short period of time and doing nothing else for a minute gives a much higher APM than doing the same number of commands in that minute but over a more spread out period.