Collect all ideas even the ones you think are dumb.

What sounds dumb at the surface may hold a hidden truth. The person who came up with the stupid idea about the pet rock was probably laughing at it. It made no sense but it made lots of money.

Sometimes at the center of the dumb idea lies a concept not accessible by normal approaches. Look deep into the idea and examine it from different directions.

When the paper run was wrong it came out fluffy instead of smooth. The proper thing to do would be to throw out the batch and go on. Some poor cluck tried it where regular paper had no purpose to be. They found out the dumb mistake sucked up water. So paper towels were born out of an error.

Extract the reason the idea seems dumb and what it might mean. Examine the might very carefully the suggestions it starts can lead to unexpected areas.  Use the branching technique put it into  new areas.  An idea that is bad for one use might be great in a different setting. The starting point for the idea came from an area that might easily be ignored. So where the extracted idea takes you might be entirely unexpected.