Hi Isabella,
I still don't have a solid view on how astrology and reincarnation intertwine exactly. I also don't particularly believe in the concept of an uninterrupted (and unchangeable?) entity like a soul. I think each one of us is an unique person: a mix of DNA combination, epigenetic effect, astrological and environmental influences. Of these, the DNA and epigenetics are the strongest determiners for how we'll look, behave, what our personality in life will be and how our life will turn out. DNA on its own is a very very unique thing which I am still exploring, but it's the main thing that means you're a human with their own unique behavior and fate, and, say, a dog born with exactly the same natal horoscope as yours has a totally different life experience.
I think that all of reality is a (mental) field of sorts, an infinite holographic field of data patterns and vibrations. When a person has a certain experience, it causes permanent changes in the person - be it in bodily form, or mind. Since all of reality is quantumly entangled, this means we have access to this holographic wholeness at any point of time. When a human is in the process of being formed (i.e. a fetus), atoms and molecules are arranged into proteins and into more complex forms following information that is stored in the DNA _and_ in the universal informational field. Now, this information field holds information about absolutely every experience that was ever experienced. The experiences of all forms that existed before us, including all primitive forms of life (single-celled organisms), more complex forms, etc. lead to, evolved into, the form we're today. This being of ours is dependent on the whole Solar system (and cosmos in fact), because this Reality was designed (or it self-emerged, don't know about that) in a way as to expand the awareness level of the forms within it. Single-celled organisms have extremely low level of awareness about their environment, slightly more complex organisms may have eyesight or hear sounds, etc. And mammals are currently the most advanced organisms in terms of level of awareness right now. So this system, our Reality, is exploring itself by raising the level of awareness, through evolution, of the actor-observers within it. Each experience raises awareness, having a human body is also an experience which we evolved to. Just slow down the rotational rate of Saturn by, say, 5%, this would shift Jupiter to a different orbit, which would move Mars a little.. and then the Earth and the Moon would be a totally different place (say the Earth would be then a bit closer to the Sun, which would raise the surface temperature and would prohibit from certain forms of protein to be formed), on which life could possibly not emerge or would emerge as totally different forms. So, life on Earth, our bodies and our minds, are very closely linked to the Cosmos. That's why in Hermetics they say "as above, so below; as below, so above". Our minds and bodies are unconsciously harmonized to this whole Reality (that is the goal of life anyway!).
OK, I digress...
From a more astrological perspective, Edgar Cayce and Hermetic sources give a good idea on what to explore. Mostly, it's a Moon-Sun-Saturn thing. For a resume of Cayce's views, check out this:
https://soulsurvivorbook.wordpress.com/2009/11/21/a-new-astrological-chart-reading/ post about the famous Leininger reincarnation case. In Hermeticism, there are different views, but most importantly it's considered that Saturn should be having an exact aspect (a conjunction, opposition or a square... no trines or sextiles) to the past life's Saturn, Sun or Moon.
Then a question arises: When can we say that a person has been reincarnated? If the current life persona is a different sex, has different eye and hair color, has a different voice tembre, a different ethnic background, has different interests... but he remembers something from his "past life"? Should we say it's a "past life", or a transfer of memories? This new person's mind (Moon and Mercury in astrology) is somehow influenced by patterns left out from the past life person.
Basically, just look at what we humans are: a combination of patterns. We have patterns of proteins forming our bodies. Patterns of proteins forming neurons, which combine within our brains and store our thought patterns and memories.
Check out this article:
http://www.dailymail.co.uk/femail/a...-strangers-brought-Finding-Twin-Stranger.html
it's about people who are "twin strangers", i.e. people who are very alike, but are not related. Notice that not only are they looking similar (well, not as identical as real twins), many of them also share the same interests. Real twins, or even triplets, or quadruplets -they are not the "reincarnation" of the same past life person.
With that said, our experiences and intentions DO matter and affect reality forever. Our experiences, as said, are encoded in the information field and affect the organization of proteins in new life forms. And our intentions influence reality directly, we have a very powerful quantum computer in our brains - the neo-cortex. We have it now because for millions of years before us other beings have experienced and experienced and experienced so so much.
TL;DR: I don't believe in reincarnation with a soul. All beings, including humans, are patterns of matter that are organized according to certain rules. These rules are encoded in the DNA, epigenetic effect and the universal information field. The universal information field stores the experience of everybody before us (and living now too, in fact). Having a body in the form of a person is also an experience. Having a human mind is also an experience. Our experiences and intentions matter to the whole of reality.
Please excuse me for the long post! Cheers!