Repeating dream signs
This is easily found by use of recall technique and a journal. Do you dream of schools but haven’t been there for years? I have a snow owl that has visited my dreams for 10 years and is in my dream log at least every 2 months and sometimes several times a week. The snow owl dream sign became quite comical when I saw one in the real world and stood there doing reality checks and found myself quite disappointed yet excited to see a real one.
In my dream journal I will go back through and highlight or underline signs and common themes. This along with constant reality checks may lead you to watch a particular area such as items, animals or whatever is the most common type of sign you have remembered and recorded. Once you form the habit and tune your brain to look for these signs they will become much easier to notice in dreams and trigger memory and lucid dreaming.