I'm working up a class on scene pacing, so I've been looking at problem scenes and seeing how the pacing can be improved by intensifying the conflict. So right now I'm thinking that a little mind-shift can help as we structure and revise a scene:
Scene agenda. There are scenes which can be fun-- heroine and her friend dissing the ex-boyfriend, or hero sitting in a meeting and cynically making mental bets about which of his colleagues is going to say something stupid or offensive. Those can be fun and funny. However, does the character has some goal beyond, you know, just sitting there being funny? There's going to be more urgency if there's a goal, and a goal is going to change the way the character acts and thinks in the scene.
For example, here you have two friends sitting in the living room with, I don't know, a Johnny Depp DVD going, and the wine is flowing, and they're trading confidences about their old boyfriends. Fun, right? (Yeah, guys, women readers will eat this up. :) Now imagine how the presentation and intensity of this will change when I add this in. Heroine has had a secret crush o friend's last ex, and now that he's available, well, she's thinking that maybe she'll go after him. I mean, just give him a call, nothing too stalkerish.
Whoa. Suddenly the fun ex-dissing scene has more reason for being, huh? And it's got more of a narrative purpose, and the heroine Mary has something to do besides making sure she gets the last glass of Malbec and remembering the name of the guy who dumped her (and totally broke her heart) in 11th grade. Now maybe she'll focus her attention. What's she want? She wants to make sure that friend Jane didn't break up with him for a really good reason, like he ships his laundry FedEx to his mother, because she's the only one who can do his underwear so it doesn't chafe. And she wants to know that Jane is totally over him and Mary can go after him without violating friendship ethics. See how that goal creates an agenda for her actions in the scene? Now maybe Mary's comments will have a little bit of an edge, because they won't be idle man-bashing comments, but pointed towards learning more (without maybe tipping her hand). She'll kind of casually prompt Jane to tell more about the breakup (and how good to learn that the problem is that Jane doesn't want to settle down and John is the type of guy who wants to commit), and maybe also make some feelers about whether Jane has moved on to another relationship and emotionally left John behind.
Another problem I see in scenes is that the writer loses track of the character's goal while creating the scene. This is actually more of a problem in "fun scenes" that showcase the author's (and/or character's) imagination or humor or prose. Here's a great scene of the protagonist landing on a new planet and exploring the landscape! What an opportunity for description, world-building, even adventure (as he is attacked by native beasts or runs from a sandstorm). But ... all that fun stuff will have more propulsion, thus more intense pace, if the character not only gets to observe and walk around, but has some purpose for doing so. And often the character does-- he's not on this planet just for fun, but to see if his shipmates can land here for some needed shoreleave. Or he's searching for a specific type of foliage with the right vitamin to cure the epidemic of scurvy on the ship.
Sometimes, the writer loses track of what the actual agenda of the scene is, what the scene protagonist is trying to accomplish. Let's think about the hero sitting in the meeting at work. Well, of course, he comes into this scene with the goal he started the book with, maybe getting a promotion. That is going to change the way he responds to his colleagues. He's not just going to mentally laugh at something stupid said by a rival for promotion, he's going to maybe even try to subtly goad the most annoying one to say something particularly dumb or racist or sexist, to reveal his/her unworthiness for the position.
So every scene should in some way show the character (I mean, the scene's protagonist or central character) acting and reacting with the motivation or goal in mind. Their ambition/desire doesn't take a vacation. And if he should find himself going several hours without thinking of the goal or acting to fulfill the motivation, then it should be a conflict. For example, let's say our ambitious young employee finds himself taking an afternoon off to go see some young woman play on the company softball team. Sometime during this scene, he should probably note that he's lost his focus, that he doesn't know what's come over him--- something that indicates that the goal hasn't disappeared even if something is beginning to distract him. He should notice that he's being distracted from what before he considered all important.
This is probably more common with character-oriented and/or relationship novels, because often the whole point of the book is to change the priorities of the protagonist-- but the initial goal still matters, even if-- especially if-- he's going to sacrifice it later.
And in individual scenes, characters can have goals or motivations that are specific to that moment. Let them act and react with that in mind. If you're worried that your story has gotten too episodic, that there isn't enough narrative thrust or forward motion, go back to your scenes. Does the character have an agenda that connects to some arc or journey? Make sure that the agenda is part of the scene.