Dear Retinoid, Thanks for the reply.
(1st know that I primarily use the tropical zodiac now along with Jyotish Techniques. I never learned Western, and only studied Jyotish. However, I have found that when using the tropical zodiac with sidereal nakshatras, many jyotish techniques make sense and actually work, where they didn't before.) (Also note, that you don't have to use a tropical chart, as people have been using the sidereal in Jyotish for a long time, I and many of my colleagues have just found the tropical chart to work better, like it filled in missing puzzle pieces.)
So from my perspective I would shift everything over to a tropical chart.
Then you can use Jaimini techniques very well to this end. Once you have the tropical positions, you want to see what the planet in highest degree is (excluding the nodes). This becomes your atmakaraka, or indicator of the soul.
All the qualities attributed to that planet gives a very strong indication of your expression and soul character in this life.
Then you look to see what sign the atmakaraka is in in the Navamsha. The atmakaraka is determined from your birth chart. Then you see where that planet is located in the 9th divisional chart. What ever sign that is in, shows your inner convictions and the things you are working with in this lifetime. So take note of the characteristics of that sign, and synthesize them with your atmakaraka.
Planets in the 6th or 8th can show a lot of conflict, combativeness or drama in one's nature. This is not a judgement of good or bad, just a quality of those houses. People with placements hear usually experience a lot of frustration, sudden changes, and unexpected events in ones life. On the other hand planets in the angles, or in the 5th or 9th allow the life to flow more smoothly, like driving on a paved road with less worries.
Malefics in the 9th from the svamsha (this is the sign the atmakaraka is in in the navamsha, mentioned above) can show offence to one's guru or tradition and give breaks in the realms of higher knowledge. Lots of westerners who are interested in yoga or vedic astrology or other cultures have this, as it shows "offence" to one's culture. People with benefic planets here are usually born into cultures that support their innate nature.
Pioneers, revolutionaries, people who are happy in other cultures often have strongly placed malefics in good dignity.
On another note, you can look at the planets in the 10th from the svamsha in the navamsha, to get ideas about purpose and direction. Planets in the 10th from the svamsha will often trigger one's purpose. If there are no planets there, then use jaimini's rashi aspects to see what planets are influencing the 10th. Or just note the sign the 10th rashi from the svamsha falls in. All these when synthesized serve as the building blocks for assessing one's soul nature and possibility for fulfillment in purpose.
(Note: when counting rashis from the svamsha, you count forward (like you normally would when reading a chart) if the sign is an odd sign and you count backwards if its an even sign).
The best software I've found that shows Jaimini and allows you to use a tropical zodiac and sidereal nakshatras is
Vedic Astrological Software I use called Kala. It is quite in depth, and a lot of fun for the research minded astrologer.