Steep slopes work OK with short trains. But they also require one or more of the following operating techniques/strategies:
1. Constant attention to the throttle to give more voltage up and less voltage down the grade.
or...
2. Some means of supplying less voltage on the downhill side by isolating that track section and reducing voltage by some means (diodes, separate transformer or throttle setting, etc.) in that block.
or...
3. Locomotives with some sort of speed control electronics such as Proto2/3, ERR cruise commander, EOB, or Odyssey. ERR cruise is probably the simplest and least expensive (but not cheap!) retrofit for currently owned engines.
or...
4. As Dennis implied, experiment with different % grades for the uphill vs. downhill runs.
As far as the fallacy of learning all you need to know from a forum, newcomers should realize that there is still an important place for magazines, books, advice from local hobby shop personnel, and, above all, your own experiences. It doesn't happen overnight and the first attempts at layout building are seldom perfect. That's all part of the fun, and is what makes model railroading a lifetime hobby for many of us. 
Jim
