The Tips in detail

 "Dirty is Good."

A typical problem in computer-generated images/animations is that most of the time, objects look too perfect and certainly too clean.

Here's a quick way to make them look a little dirtier:

Use a MIX map in the Diffuse channel. Set Map #1 to the map of your choice (e.g. Bitmap: Newdone.JPG) and copy Map #1 to the MAP #2 slot. Go to Map #2 and insert an RGB Tint map and keep the old map as a Sub Map. Make the three colors of the RGB Tint map darker. (This, in effect, will darken your bitmap). Last, go back to the MIX level and use a Mix Amount map based on Noise (or maybe a gradient with built-in Noise). Render your scene and see how the two variations blend together.