I've been reading Do It Tomorrow and Other Secrets of Time Management by Mark Forster. It was recommended to me by someone who ironically doesn't follow the principles (it's quite funny actually), and in the first chapter Forster talks about Thought - Decision - Action versus Stimulus - Response, in response to prompts such as a shower of emails or a sudden phone call.

The Thought - Decision - Action is when you essentially already have a default option in place for a given prompt. Once a task appears, you make plans to complete it, or when you get an email, you make sure to either respond right away, or set a time to respond, for example. Stimulus - Response is when you don't have a default, or a certain stimulus makes you do something you hadn't really planned for. Stimulus - Response is when you put off responding to an email to a later date, and then inevitably forget about it (I'm really bad at this!!!).

Obviously the Thought - Decision - Action sequence is much more efficient at helping you manage your time, and I've been trying to incorporate it more and more into my day. It basically means being more aware of what you do when you are prompted, and then making sure that these prompts lead to action. In other words, Thought - Decision - Action is like building reflexes in your brain. These default options take the time and effort given to decision making out of the equation, the thinking has already been thought, and make it much easier to just get out there and do what needs to be done.

Action over thinking, not overthinking action.