First, Abram goes back to where he has already encountered God, and built an altar to remember the occasion. He turns his life outward in seeking for God rather than his own interests.
Lot looks at his immediate surrounding, looking for what will be most helpful to him. He turns his life inward. The plain of the Jordan is reminiscent of Eden (and ironically, Egypt), so Lot, who has heard of the garden, chooses that direction. Of course, with this land comes the people who live there. The men of Sodom and Gomorrah receive a negative report before we even get to know them.
On the other hand, after lot leaves, God rewards Abram for his faithfulness thus far. He is given the promise of land and offspring (as before). God reaffirms the previous blessing, though the evidence of that blessing is not yet realized, especially the part about children. Abram builds an altar as a response. It's almost as if by going back to the last time he heard God, Abram starts over from his last encounter.
Consequences: Lot eventually gets captured, and Abram does the rescuing. The story of the war itself is interesting, but I'm not going to focus on it. Though consider that the word king might not mean a medieval king who had absolute rule, but the leader of a tribe since society was primarily tribal at that point. After the rescue, Abram does not turn inward with the treasures, but gives what he already had away. Here is one of the most perplexing and rich stories in Genesis. The story of Melchizedek.
We know nothing of Mel. He is a priest (which was normal for that time, as every family would probably have had some form of priest). He is also a king. The two basically celebrate communion (or the communal meal according to Phyllis Tickle), and Melchizedek blesses Abram. Abram responds by tithing to Melchizedek, even before the law of tithing has been written. Here are the first ever described spiritual disciplines. Mel is to some extent a theophany insofar as he represents the presence of God on earth. Can you imagine a mysterious figure approaching you after a battle, and then feeling the need to give him your stuff? Suddenly this encounter ends.
Jesus, of course, is later realized as having the same authority and even more as Melchizedek. The weird thing about Jesus being a priest king is that Israel's expectation for a Messiah was generally either priestly (religious) or kingly (political), but not both (some believed in two messiahs though).