The most consistent element of dream interpretation or analysis is that everyone will disagree. This applies to researchers and psychologists as well as the general public; if you describe your most recent dream to four different people and ask for their opinions, it's very likely that you will get four wildly different interpretations. That being said, there are a few common symbols in our dreams that have been mostly agreed to carry a particular significance, whether through psychological analysis or general public consensus. You could spend days combing through the myriad "dream dictionary" websites out there and figure out which symbols have any degree of consistency in their meanings, but it's your lucky day! I've already done it for you! So if any of these symbols have turned up in your dreams lately, here's a quick run-down of what they probably mean:
FALLING
If you dream that you are in a free-fall or falling from a high place, you're probably feeling some loss of control or lack of support. This could apply to a job, a personal relationship, family life, or anything else that makes sense to you.
From a physiological standpoint, dreaming of falling can also be a reflection of your physical state at that time. Have you ever been half-asleep, within seconds of falling asleep completely, and then suddenly felt like you had missed a step going down the stairs or stepped into a deep hole you hadn't noticed? When your body is preparing for sleep, it gradually disengages each of your muscles until you are completely relaxed. Often when this happens, your body feels totally unsupported (regardless of the bed underneath you), in free fall, and quickly tenses up either to stabilize or to brace for some kind of impact. (This is also known as a "myoclonic jerk", which is a cool phrase you can throw around to sound smart.)
NAKED
Dreams of nakedness are famously common. Dreaming that you are naked in front of a group of coworkers, friends, classmates, family, etc. most likely signifies a fear or a sense of being exposed. This coincidentally lines up well with the phrase "naked truth"; it might mean that you are hiding something that you are afraid will be uncovered.
PREGNANT
Something is growing in your life; it could be a new idea or project, a new relationship, or something you're thinking about starting. This typically has positive associations, as you might be excited or pleasantly anxious about this new element of your life.
MIRRORS
As you might expect, the presence of a mirror deals with thoughts of how others see you or how you see yourself. There is no end of variations to this symbol, and the specificity of the interpretation depends mostly on what appears in the reflection. If you look into a mirror in a dream and see that you have no reflection, it could point to a struggle with personal identity. Because mirrors have a long mythological association with truth, you might see a reflection of your "true self" or "true nature", whatever that means to you.
SEX
At the risk of getting a little risqué, sex dreams are so common that I just can't leave them out. Like mirrors, the particulars of interpretation depend pretty heavily on the particulars of the dream. Generally speaking, these dreams say more about your personality than your sex drive. The two most important things to notice are 1) who the other person is, and 2) the nature of the sex. Both/either of these things will likely point out a quality that you either have noticed and enjoyed in yourself or feel that you would like to express more of. For example, if the sex was patient and gentle, you might be appreciating your own capacity for patience and gentleness, or you might feel that you need to practice more of those qualities in your daily life. If your partner in the dream is someone you have admired for their spontaneity and freedom, that might reflect a desire to become more like them. Conversely, it could simply reflect a base-level sexual desire, or it might point out a desire for a particular sexual relationship that you are not consciously aware of.
As a side note, many of these dreams and symbols can be taken literally as well. Falling could result from a fear of heights, pregnancy could appear in a dream while you are trying to get pregnant, and, of course, a sex dream might just be a sex dream.
THE BOTTOM LINE... is that dream interpretation is nowhere near an exact science. Many very intelligent and well-respected people have spent time studying the mystery of dreams, and most of them have come up with very different and conflicting ideas. What keeps us trying, though, is our own curiosity. If we can decode some of the clearer elements of our dreams, we may have a shot at gaining a better view of our subconscious mind and what our dreams are trying to tell us.