Clutter is like mold. If you don't take action to get rid of it, it will continue to grow and will eventually be a hazard to your health.
When you purchase something, pay attention to how it looks when it comes out of the box or package. It is likely that the key to storing it in a nice neat way is how it was when you bought it. Think about a fitted sheet. Folding them seem impossible but when they are in the package at the store they are folded neatly with uniform corners and a perfect square shape.
p.s. If you wonder how to fold a fitted sheet, Marsha Stewart has a YouTube video that can teach you how. Just search "fitted sheet Martha" on YouTube.
When you are starting an organizing project, it is just as important to ask "What is working?" as it is to ask "What is not working?."
For inspiration on how to fix problems, model solutions after what IS working. An example of what to look for might be to notice whether items behind closed cabinets tend to stay more organized or those in open top bins on shelves.
I have two young children (ages 3 and 5). When I am cooking dinner I like to have them in the kitchen with me.
To keep them busy and out of each other's hair, I designated a cupboard as their "activity center." I asked for their help in designing the space. They told me the types of things they would like to have there and I determined how much of each category and what containers were appropriate. Getting them involved in the design gave them ownership of the space and I have found that they are more likely to return items back to their proper places when I do involve them.
On the top shelf, I used a magazine holder on its size to contain stickers (in a plastic pouch) and a folder for completed artwork they decide to keep. On the horizontal trays we have loose colored paper/construction paper and coloring books. My oldest daughter's journal is next to the horizontal trays on the right.
We have crayons, markers, and colored pencils in containers on the lower shelf. (My oldest wanted them separated by type.....like mother, like daughter.) I used another magazine holder for educational workbooks on the right. These are strategically placed somewhat out of view so the kids aren't using them as coloring books. (These types of workbooks are more for one-on-one time with me.)
This system has been working quite well. As the kids get older and their interests change, so will this space. For now we are enjoying cooking time bliss.