One big difference between the two (Marvel/DC) is just the overall tone of the movies. DC movies tend to take place in a dark dreary world and the heroes have a dour personality. Meanwhile, Marvel makes movies where the world is brighter and the heroes are sarcastic and light-hearted.
DC tried to go that direction with Green Lantern, but the writing was absolutely terrible and the movie flopped.
I think most comics, these days, are more in line with what DC has done with their movies. The stories are dark and edgy. The world is portrayed with a lot of blacks, grays and dark colors, and less bright yellows, reds, etc.
Marvel seems to trend more toward the style of comics from the 70's, 80's and 90's. Those artists used mostly bright colors and contrasted that with a small amount of dark colors.
That's just the way I see it. I don't know if either company has a directive to produce movies in a particular style. But, I don't think it can be debated that Marvel has a formula that is working and DC is now trying to figure out how to catch up to them.