You might have scenes just to add local color or history to your story, but plot and character are your primary focus. The best vehicle for bringing your characters to life and advancing your plot is dialogue. For my money, dialogue is what makes the difference between a great writer and an amateur. More than anything, dialogue is going to bridge the gap within each scene and eventually lead the reader to your dynamite ending. The reader will believe your ending because your characters will have revealed their motivations through the use of dialogue.
All dialogue is action and reaction.
Dialogue stems from your characters and will never work well unless you know your characters. You must know her well enough to know whether she drinks, spits or chews. Beginning writers get a plot idea, create some characters and then start to write. It's fun to write. There's a glory and a joy in writing.