At the beginning of the game, instead of drawing 2 cards from your faction deck, look at 4 cards, and choose 2 to keep. Shuffle the other two cards into your deck.
I know that getting only end-game VP buildings during turn 1 can be a big setback, and this variant would be easy for experienced players, and possibly even the playing field.
After about 20 games (mainly solo) i basically had the same idea, but i went a little further. For my starting hand i draw 4 cards from the common and from the faction dect and pick two of each. The other cards get discarded (mainly as a little penalty for having more choices in the first place).