You can read a ton of books, take writing courses, get critiques like you always have, or you can spend a couple of hours a day for a few days or even a week watching the work of writers who have mastered all these skills. Infamous for their ability to suck in a new viewer, sneered upon even more than romance writers, you gotta hand it to them. Soap opera script writers know what they're doing.
Their plots and subplots are written very well and are extremely well-balanced. They have to be. Remember, they have to keep an audience interested enough that they'll wait through some of the most obnoxious commercials aired on tv, second only to late night infomercials, to continue watching. During the dread commercial break a viewer can easily switch to a different soap or plug in a non-commercial-laden DVD.
Their characterization is strong. The viewers may know who the bad guys are, but not all the characters do know who the bad guys are and that makes for a lot of fun. (Take a lesson from that right there.) They write bitches like no one else and put honey in their mouths when those bitches are a wooing. If you have trouble writing good guys that aren't boring, look no farther. Each character has a distinct voice, goals, agenda--they're well-rounded and unique.
Suspense and tension? They've taken it to extremes that have become laughable in the tv screenwriting industry, turning the cliff-hanger into a cliche' and drama into new heights (or lows, if you prefer) of melodrama. What's beautiful about it as far as learning how to do it from a writing perspective is that the snippets of plot are broken down into very short frames and you can examine the tension arch in bold relief.
The writing has to be good or there would be no audience. In matter of fact they have a huge audience, one any writer would envy. They have to be able to pull in a new viewer in just a few seconds in the middle of the story, with no recap because they never know when a new viewer will come in. That alone I find fascinating, that the writing can bring in a viewer into the story even though that viewer has no idea (initially) what's going on.
I bet you think I'm joking but I'm not. Give it a try. Just remember, they are addicting. Whole magazines and forums are devoted to them. There was even a paranormal one I came very close to becoming addicted to when I last had the flu. It's worth the risk for a quick, dirty and efficient lesson in effective writing techniques.