"A good plan violently executed right now is far better than a perfect plan executed next week." -- George S. Patton

Planning is simultaneously important and futile.  Important because it is critical that we examine what we intend to do and make the best prediction as to how we might accomplish it, but futile because no matter what we won't see all the variables and the other guy (the competition) has a bad habit of not following the plan rendering it less than completely successful.  Victories are won by planning more times than they are by improvisation, but adherence to a failed plan in absence of free thought has also led to far more losses than improvisation ever has.  Plans are like cookies, they should be made, must be made, but should be discarded if they get burned or go bad.
Looking back at my competitive career, I have been a far more careful planner when it came to striking (muay thai and mixed-martial arts) than jiu-jitsu.  Perhaps this is an artifact of competing in many more sport jiu-jitsu tournaments than muay thai or mixed-martial arts.  Things that feel more routine require less planning.  However, at the higher levels of competition, every competitive edge and especially planning becomes more important.
An important aspect of being "game" is willingness to enter the fray or the joy of locking horns.  Too often, and I see this in myself, planning is a list of reactions to what the other guy does.  To quote Marcelo Garcia, "Play your game, don't worry about what the other guy does."  If something doesn't work you have a back-up to that, but don't wait for your opponent to do something before you.  This isn't an conversation, it is not even an argument, you are giving a lecture and maybe you will grant your opponent a few questions at the end after your presentation is complete,
To that end I have designed a first draft of a Brazilian Jiu-Jitsu / Sport Jiu-Jitsu / Submission Wrestling Game Planning Worksheet.  It begins with a goal statement describing what tournament this is for.  It then has brief section on the stand-up phase and how you intend on getting the fight to the mats and where you would optimally like to be when that happens. You then describe how you would attack from your goal position followed by the position you think is the back-up or most likely position you would end up in when not in your best position.  Then you review what you would do if you screwed up, i.e. what happens if you make a mistake and end up in the position you hate most.  Here you describe how you would escape and get back to winning the fight.  Finally you should list two variants to attacks you described earlier in your plan as well as three things you need to improve on.