How do I notice dream signs?

How do I notice dream signs? I try but like last night I was shopping on mars and it never occured to me that it was a dream. Is there any way I can control myself so I know when I am in a dream?

Start a dream journal. At the end of each entry, read over it and make a list of prominent things that you notice in your dreams.

For example, I have a lot of dreams about going on long walks or drives. So, every time I'm in my car driving or hiking or walking down the street I do a reality check. When I'm doing these things in my dreams, I do reality checks too.

It might take a while to find your best dream signs, but with enough journaling you should be able to find them.

just keep a journal. it could be anything. for me it was a person i used to know in elementary, so its not always so surreal.

There is dream journal software on the internet that you can type up your dreams in, and later you can use a search function to look for recurring themes in your dreams. Pretty nifty, I might say.