hi danubhe ~
Have a look at this reading, which was brilliant and done by Thirteen who is a fantastic reader. It may give you some ideas. The Konraad's is a very comprehensive spread and looks at how themes in the present can reflect past life themes.
There are also many shorter and simpler spreads, SongDeva and Contrascarpe developed one here, I think, and there are many others around. Orphales Tarot had one on their site which I quite like.
LawGuy51 posted an excellent past lives karma spread here a few weeks ago.
Please send a PM if I can help any more. I love them myself but they take a lot out of you