Learn to write readable papers for grad school and more
Standford University Course, Writing in the Sciences, is a free massive online open course at Coursera. I'm taking it and learning to cut the excess words and jargon that confuses even peers when they read those peer-reviewed papers. When you have to re-read one sentence five times to understand what the author is saying, it is not always because you're not smart enough. It really is time to write well and clearly and stop with the wordy-ness that often sounds intellectual, but really is not.
"This course teaches scientists to become more effective writers, using practical examples and exercises. Topics include: principles of good writing, tricks for writing faster and with less anxiety, the format of a scientific manuscript, and issues in publication and peer review."