Does anyone do any planning on their game? Do any one use VTOC diagrams, sub problem table's and Algorithms?

When i first started to code in flash i developed a bad habbit of just skip planning and just code my app's and game's. And now that i got taught it was bad to do that and taught and the correct way to go about it the quality of my work and how nice it runs has improved a great deal. At first when i was getting taught about correct planning i just thought it's just extra work that you don't need. But when you start to do the stages in planning and testing your algorithm you will find that all you will need to do is convert you algorithm into code it will cancel all logical errors if checked properly. And make the code go from noodle code to nice structured code with less variables and no logical errors.

What i do to solve game problems is, work out sub problems and then define my inputs and what i want and then work out how i am going to use those inputs and get my outputs from them. I then use this written diagram to write my algorithm. Test that by using test data to find logical errors and then simply code. It sound's like alot of work but it will save you time. Because noodle code is hard to fix.

So i was just wondering how everyone goes about it. Go straight to coding or do the planning.