Showdown
Sayles films Charle and Buddy facing off against each other early in the film in a restaurant. Buddy's just told Charlie he won't be a part of his money schemes. Sayles frames the two men with patrons from the restaurant. Charlie has his hand on his gun and Buddy has his on the table. It's a new age image of the classic showdown.
Memory
Sayles uses the dissolve in order to show the story shifting from the present time into a memory. We see this in the bar as it dissolves from present day into the bar in the past as the story is recounted. It's a simple technique to separate the timelines and keep the story flowing fluidly forward.
Pilar and Sam
Throughout the film we see connections between Pilar and Sam through Sayles' imagery. Pilar talks about love in the car with her daughter and we see a shot of Sam walking down the street. Sayles strategically places Sam and Pilar in back to back editing cuts in order to create a connection between the two of them.
The River
We see Sayles use the river as the backdrop for Pilar and Sam as they talk cryptically about their relationship. Sayles pans down to the river and uses it as a way to cut to the younger versions of the two characters. The river shows that the love that had run between the two of them is still very much there.