Being born on a cusp (23 July), half of the papers had me as a Leo and the other half as a Cancer. I would read both and pick the one I liked best
I don't take them seriously and rarely read them, but believe that they might have some utility from a Freudian point of view... Most of the daily capsule horoscopes are written in broad, general terms. It is possible that on reading a horoscope, the reader's subconscious would affect his/her interpretation of that horoscope. It thereby acts as a sounding board, allowing thoughts to crystallise and bringing them to the forefront of consciousness. I point out that any such utility, real or imagined, is completely tangential to the intended purpose of the horoscope.
I knew a bloke who was seriously into astrology. After expressing curiosity about exactly what he did, he took down my birth details, and the next time I saw him he produced one of those "natal chart" thingies with all the planets and other bodies in various positions at the time of my birth. He proceeded to explain the whole thing to me. I did gain a better appreciation of the whole astrology thing, and how it might be useful to anyone who was seriously in to it. Again, much of the utility I see is in the fact that the results and interpretation are broad and ill-defined, and what can be learned about an individual is more from his own interpretation of the chart, rather than any inherent property of the chart itself. I don't for a second believe that the positions of astral bodies at the moment of your birth has any influence on you, your personality or your life. One could generate a natal chart completely at random, and it would still work as a sounding board for the subject's own thoughts. Again I stress that this property is entirely tangential to the proclaimed purpose of astrology.