I view horoscopes as entertainment only. If you rely on past history and present trend, it is possible to make decent predictions based solely on these pieces of information alone, and tie in the horoscope to get the illusion of accuracy (in fact, the better psychics actually do this). A good, honest psychic will rely heavily on past history and present trend, and get close to perfect accuracy (allowing for the inevitable changes that are unpredictable). Notably, those "positive thinking" cults rely on this--people tend to think along the lines of past history and present trend. If these are negative, negative thinking results and is usually correct--and forced positive thinking will always (or almost always) go bust. If good things tend to happen, those people will think positively based on past history and present trend, and usually be correct.
In fact, the horoscopes I have read in the newspapers are almost always wrong. Those horoscopes take a few basic rules and compose a guess about what is coming based on those rules, and are usually not accurate. Still, they can be entertaining to read--plus a slap in Jehovah's face.