Re: Plotting
All these methods (celtic knotwork, chess, road trip, etc.) all point to one thing: movement. Plot is about movement: how do you move a set of characters and "things" through time/space to reach your destination (climax)?
Put your characters in a situation/place and have them do something. If you know the "feel" of these characters, then let them loose. The important thing is, have them do something that has consequences -- consequences lead to plot. If you just have people sit around talking about feelings and stuff, you will find it hard to "move" them, unless, in your dialogue you indicate movement, such as:
"I don't love you anymore."
"In that case, I am moving to Paris with your only child."
"You can't do that!"
"Watch me."
-- consequences... your next plot would happen in Paris, for example, when one character chases after the other. Or, in the bedroom when one character is murdered... so many different options, depending on your story, theme and ending.
As your characters do things that lead to consequences, you will get a better feel of where they should be in the next scenes. If you have multiple treads (celtic knotwork), explore those threads, intercutting between them. The point is, move them along that line toward end goal.
Again, it's all about movement.
Use everything you can to create movements: props (clocks, money, airline tickets, bomb, sexy underwear...), characters (somebody does something that prompts more actions..), dialogue (to indicate directions, intention that lead to action), conflicts (conflict almost always result in actions)...