Be prepared for the unexpected, the illogical, the humorous, even the grotesque. It may hold an important key to your interpretation. I use the margins to add my own remarks and interpretations that come up while I'm recording the dream. That way, I have an accurate record of the dream events AND my first interpretations. There may come a time when you will interpret your dream differently.
Symbols are open to interpretation and context is highly important.
You are always the best authority on the meaning of your own dreams. But if you're having trouble understanding a dream and you have a trusted friend to talk it over with, do so within the first few days of the dream while it's fresh in your mind. Sometimes, the very act of talking the dream over will help you break through a block you've had in understanding it. Pick a friend who thinks like you do and who's a good enough listener to let YOU work it out. Why dreams are important to the creative process and how can you use them.