Walls are an integral part of any home building. Walls help to create the perception of "space" and provide privacy in to interior rooms. Wall decorating does impact in a great extent in home interiors.
There are many ways to decorate a wall. Depending upon the location of wall in your home, many themes can be considered for the best effect. Most homes have some common ares that are necessary for a healthy living such as

1) Living room
2) Bedrooms
3) Kitchen
4) Bathrooms
5) Family Room
6) Dining Room

Depending upon the size and area of the home the internal rooms and the plan will vary. If you want to decorate internal walls, it is absolutely necessary to first understand where the wall is located and what's the purpose of the room itself.

For example the function and the activities carried out in a home theater will greatly differ from a bedroom or living room and so will the decorating theme. So wall decorating ideas will greatly differ from room to room. Whatever the case may be it is necessary to pick a decorating theme that will create mood necessary to inspire the users to perform the said activity with maximum efficiency.

For example if you are trying to decorate a wall of a kid's bedroom, it would be nice to create a wall decor that will inspire the kid to learn new things. In such a case a wall where the kid can write or draw pictures with chalk or sketch pen is a good idea. You can even divide the wall into two parts and use wallpaper in the form of a storyboard that will help the kid to ask questions.

Thus wall decorating becomes a self-explanatory job once you break down the whole exercise into function and theme. First find out what the requirement of the room is and then pick the most appropriate wall decorating theme