Tip #238: Extra spice

Adding a love interest is an easy way to add a bit of extra suspense, drama & conflict, to darken the dark point and sweeten the resolution of the main plot.

http://critiquecircle.com/forums.asp?action=viewforum&index=248&thread=950095

Tip #234: Plotting via character development

At the beginning of your novel, how does your protagonist understand himself? What defines him? What rules or code guide him? What assumptions are givens? What’s home base? Who’s on his side? In whose love is he secure? ... 

At the end of your novel, how has the answer changed to any of the questions above? What happens to change that opinion? Add it.

http://writerunboxed.com/2011/12/07/a-sense-of-self/

You could generate an entire outline by asking these questions.

Tip #225: Not just a prize

The role of the romantic interest is to challenge the protagonist and shock her out of her regular mental and emotional pattern.

http://screenwritingtips.blcklst.com/2012/02/screenwriting-tip-904/

Tip #183: Mystery

Mystery plots -- where our heroine needed to uncover a piece of information... as forces or people worked to keep that information from her.

http://chavelaque.blogspot.com/2011/12/behind-book-three-things-writers-can.html

Tip #140: The "love interest"

there’s a profound difference between a love interest whose only investment in the plot is their attachment to the hero, and a fully functioning character who develops into a love interest.

http://fozmeadows.wordpress.com/2011/06/27/bechdel-matters/

Tip #104: What's in a middle?

The protag can’t immediately know what to do to resolve the problems and bring about the ending... they need to figure things out piece by piece. Each clue or discovery or action brings them closer to the major event at the end of act two that sends them hurtling toward the climax.
Odds are you’ll have three to five big plot things that happen in the middle.

http://blog.janicehardy.com/2011/03/stuck-in-middle-what-makes-good-middle.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+janicehardy%2FPUtE+%28The+Other+Side+of+the+Story%29&utm_content=Google+Reader

Tip #96: Resolving conflicts

I tended to resolve... conflicts too early and too easily. Because my characters lived in the imaginary world inside my head, the conflict they experienced made me uncomfortable, and I wanted to relieve them of this discomfort. Tension and {character} frustration, however, keeps readers turning pages.

http://writerunboxed.com/2011/03/14/tough-lessons-from-a-debut-novelist-part-1/

Tip #83: Linking storylines

the A, B and C storylines in a TV episode are usually thematically linked... Even if readers don’t consciously notice it, they’ll feel it.

http://screenwritingtips.tumblr.com/ Tip #548

Tip #69: Men actually like romance...

Men actually like romance...To be specific, men like the dynamic.  Men like seeing how it matures and how it evolves and how they eventually get together...  It’s a story, same as seeing how the hero overcomes the forces of evil.

http://samsykes.com/2011/01/sam-sykes-touches-men-and-women/
{Paraphrased:} and a story where one or both of the characters are passive isn't terribly interesting.

Tip #55: Knowledge is power

Keep careful track of what your characters know and don’t know. There’s huge dramatic mileage in having your characters obfuscate, tell little lies and keep information from each other.

http://screenwritingtips.tumblr.com/ Tip #520

Tip #41: Writing the middle

keep asking, "what happens next?" and "what goes wrong?" They'll never lead you astray.
Even if they will lead your protag astray.

http://storyflip.blogspot.com/2009/04/plot-thickens.html

Tip #37: Three types of plot

there are basically three kinds of plots:
A conflict: Two people or forces in opposition to each other. This can be an internal conflict as well as an external conflict
A mystery: Where some piece of information needs to be found out: the name of the murderer, the location of an object on a quest
And a lack: Where something is missing from the protagonist's life at the beginning, and it is earned or fulfilled by the end.

http://www.cherylklein.com/id38.html

She goes on to say that one of the reasons she believes the Harry Potter series works so well is that it has all three, as well as individual plots for each of the books:

The conflict: Harry vs. Voldemort
The mystery: Why Voldemort couldn't kill baby Harry, and how the grown-up Harry can eventually defeat him
And the lack: Harry going from not having friends or family to being surrounded by them at the end of Book 7

Tip #24: Medium Stakes

the consequence will change the life of the protag, but not in any long-lasting way. It'll have an effect on the bigger story, will probably make things a bit tougher, but failing isn't going to change the protag that dramatically. Common medium stakes include choices where the protag knowingly makes things tougher on themselves for the sake of something that matters to them... It's not about worrying if the protag will win, but how this choice is going to make things worse down the road.

Given example: risking capture to rescue a friend.

http://storyflip.blogspot.com/2010/12/up-up-and-away-raising-stakes.html

Tip #23: Low Stakes

Low stakes {involve} a consequence, but it doesn't change the life {or story} of the protag all that much... It's not about if they've made the right choice, but curiosity about what that choice will be.

Given example: someone choosing between two potential loves, where either will make them happy. 

http://storyflip.blogspot.com/2010/12/up-up-and-away-raising-stakes.html