Organization, or rather lack thereof, seems to be the common problem for most students with disabilities. I hear it all the time. It usually comes in the form of homework not getting completed or paperwork never coming home. There are of course things the IEP team can do and should do to help. I find it sometimes to be a simple thing, but then a notice that the child may not see organization done at home or school or have any frame of reference to emulate.
I am, by no means, saying that parents or teachers lack organization. I am simply saying that students do not get to see the adults organizing things or know what they are doing. We need to make a conscience effort to show them and model true organization.
First find out what the main problem is and where they struggle with organization the most. Have a discussion with them about possible solutions to the problem. Once a possible solution is found go to the office supply store. While you are there have another discussion. Get the supplies that you will need. Make sure to be clear to them that if this first possible solution does not work they can try something else.
Once you are home with your supplies show them how you would use it and if possible show them samples of how you stay organized in a day. It would be more beneficial for the student to come up with the organizational methods that they think will work for them and not be told what to do. At the end of the day, they need to be motivated to do it. Revisit the methods in a week or two and encourage them to modify what is working and what is not to make the process successful.