All symbols can be personal or objective. If you can't quickly think of a personal meaning figure out the objective meaning.
People represent a sentient being. They either represent the person themselves (as they relate to you) OR a conscious or unconscious parts of yourself. Good or dark or wounded parts of yourself. OR a spiritual being, God, angels/ministering spirits(often they are just a good spirit with a specific task and are sometimes named by their purpose like speed), dark spirits, the enemy etc.
Any kind of Role, Relationship, Sex, Intimacy - could be literal or metaphorical. It's about your role and goal and relation to the other person. What is other other persons intention towards you? What's your intention towards that person? Could be towards yourself or someone else.
Animals often represent pure emotions or drives. Semi-sentient and active. Finite forces of nature. Like say the desire to find food or be comfortable. OR if they are a personal animal they can represent whatever that animal represents to you. OR sometimes they can represent dark spirits or influences or dark animalistic parts of yourself that are influencing you.
Vehicles represent what they do and how they do it. Think of how many people can be in it. How fast etc. Walking, flying and running are in this category, Its all about how you get around. If it;s just you or say a bike it could just be about you but vehicles that can move others could be pointing to a situation involving more than just yourself.
Body parts - think of what that part does and what they represents. Like teeth chew and break nutrients down so they could represent your ability to do that. Or to smile etc.
Objects - think of the technical and raw purpose of the object and how it can be metaphorical.
Plants - like objects but they are alive and non-sentient. They just exist but have purpose and grow.
Colors - what do those colors associate with you? Look up the meanings. What objects have that color. - Light illuminates so colors often modify or expand on a symbol.
Light/ color quality of the dream - It's source. Grays or real life colors often represent the Soul. Bring Vibrant colors from God, life source. Dark moody colors, from the enemy, darkness outside or from within.
Numbers - Look up number metaphor dictionaries that you relate to. Say you are a math junkie and math history means something to you. You could start there.
Motivations or Actions in the dream show you what it's all about.
Situations - think of the metaphorical representation. Does it relate to how you feel something that is going on this week?