Meal Planning

I am HORRIBLE at this!!  Why?  Because I can sit down and write out a plan for the month; but when it comes to that day...what if I don't want what's on that day's menu?  I know just switch it with something else.  Yes I can do that; but I don't. 

I had an idea...starting today.  I am going to write down everything I fix this month on a calender and then use it for next month.  I really want to know if this will help when I go shopping by decreasing the number of times I have to go and the amount of stuff I have to buy.  I know by others that it will; but I am actually excited to try it this time.  So June will be my prep month and July will be my trial run.  I also have a twist...my husband works crazy shifts so I have to plan around that too.

Any suggestions on this?  Or advice?? Pleeease!!!   

How do you guys prepare a grocery list???  How do you keep from cooking the same things over and over???  Do you ever get frustrated doing this or has it been a life saver for you???