I hate to say it, because it may sound obvious, but the best way to learn decision making is to practice decision making. IMO, CFI's in general are way to quick to fix a decision made by at student and way to quick to answer questions in the cockpit. One of my classic examples was a student who was working on her commercial and would ask me everything down to "think I should get the ATIS now?" It got to the point where most everything she'd ask me where she was asking me to make a decision would be followed by "I don't know, you're the commercial pilot".

Making bad decisions is a valuable learning tool. We as CFI's should be comfortable with our own personal limits - how far am I going to let this decision play out before I pull the plug on this error chain?

A student's understanding through consequences is much more valuable then a CFI explaining what the consequences will be. Also, once put in a situation due to their decision (good or bad), they need to see that decision out and make follow up decisions. This may be extremely uncomfortable, especially for students who are regularly fed decisions from their CFI. However, students who become comfortable making decisions turn into the best pilots.

Lastly, I believe that this is the real reason why CFIing is so important. It forces the CFI to make decisions out from under the umbrella of their CFI's ticket. It also forces the CFI to analyze the decisions made by students as good, bad or indifferent as they pertain to an error chain or successful decision making process. In many ways, freight dogs do the same thing. They make decisions that they and only they have to live or die with.

This is the biggest problem with guys hired at airlines with wet commercials. Its not really that those who paid their dues look down on these guys because they got to the bigs easy, its because when the 200 hr guy becomes captain, they will have never made a decision outside the umbrella of their CFI ticket, or Capt's ATP (besides any trouble they got into in their limited amount of solo time).

Sorry, guess that last part was a little off topic.