I think that writing a blog is also a great idea. This method help me to write often in various themes.
I can also check my groupmates' blogs, comment them. In this way of learning I see not only mistakes of my own, but also mistakes of my friends. What I like the most is that after some time I can go to my blog and read everything one more time. When I am doing that, I always find new mistakes, which I can correct.
Moreover, I think that we should have more writing lectures. One lecture in two weeks is really not enough.
But it is still better than nothing.