In addition to studying it relentlessly as Stormblood said, you have to know people. There is no better substitute in Astrology than knowing people because only then do you get the specific nuances of how others work. This can be difficult for this generation.
Case in point: HPS Maxine knew a woman with an exact Sun in Taurus-Venus in Taurus conjunction. She hogged the work bathroom for hours to do her hair and makeup. She took hours before work to do her hair and makeup. She never missed her beauty appointment on a specific day, even if her kids were starving. This wasn't out of inadequacy, it was out of a blatant superiority complex.
Plenty of people were born the same day as that lady. and, when the Sun transits through Taurus, it often forms a conjunction with Venus. Not everyone with a Sun in Taurus, Venus in Taurus conjunction is like this woman, especially if things antagonistic to the tendency of the Sun and Venus are prominent. But it always manifests in some way, even a minor way. Someone like this could express their ego through needing excessive stability. Like talking forever to make 'perfect food' that looks pretty but goes cold. They could be fanatical about having sex a certain way that makes them feel secure and 'do no wrong' but irritates all their partners, or is ultraconservative, or they go apeshit when their partners put their hair out of place (literally or figuratively). They may get irrationally irate if someone doesn't worship their pretty household objects.
If you're more antisocial, autobiographies and biographies, or reacting to current events involving public figures, are your best bet, but be aware, these can involve lies. And to get a fuller picture, you have to read about people you may not like, or are even interested in, but this is a necessity to doing Astrology well - ESPECIALLY with Synastry. Unfortunately, not all publicly available birth dates are reliable either; some celebrities do lie about their age [then again, so do people irl...]. Historical times of birth are shaky at best.
Public figures will always have more 'skewed' Astrology than the norm too because they're famous (or infamous, or victims of something).
Another thing is that sometimes things on a Chart can mean different things when it involves a person on a lower plane of development versus someone on a higher one. The birth chart of a mental defective/disabled is obvious with that one, but it applies when it concerns average vs. higher beings too.
Some people are a mix of both; they may have many high qualities but are bombarded by hideous bad luck and shit circumstances that keeps them trapped, especially if they've been cursed. The adage HP Cobra used (I think) that 'the highest were brought to the lowest keel' under the enemy applies here.
