People proceed along this quest of self-discovery in different ways.
In my opinion the best course is usually to find the answers within oneself rather than through others. For instance many people who go through "past life regression" therapies often later discover that they were convinced of inaccurate information. If the therapist, for instance, is really into ancient Greece (Japan, Egypt etc) a disproportionate number of their clients tend to "discover" past lines in ancient Greece (Japan, Egypt etc). This is sometimes explained as the client being "drawn to" the therapist because they share past experiences... can't really argue/prove this either way but to me it is problematic.
I suggest private meditation and the keeping of a dream journal. Before going to sleep spend a few minutes in quiet meditation/contemplation willing yourself to remember your past lives. Then slip into sleep. When you wake up immediately take the journal and begin writing your dreams down, even if only snippets: a door, a gate, a smell, etc. By doing this you will be programing your "higher self" to reveal more and more information to your conscious and dream mind.
It can also be helpful to keep a second journal and begin writing a story based on your dreams as they unfold. In time many people find the remembered pieces coming together. As they do some pieces may be variable if you are so inclined. For instance SAY you see a sign: Jones Inn, establish 1784. Do a web search on it, see if you can find anything... Much of this is detective work. If you allow others to tell you that you were healer in ancient Greece etc. you wont know if that is true or not but as you uncover information yourself you will gain a sense of certainty.
Hope this helps,
