The only way to become a better writer is to write more. And contrary to popular belief, practicing this skill does not have to be painful for students.
I love journal prompts. They force the students to think about things they may never think about, but they also give them an opportunity to pour out their inner feelings and thoughts they may never share orally. They are a perfect way for students to practice writing without realizing they are "working" on their writing skills.
I have a bundle of prompts that I use in my classroom throughout the year. They are based on current events, historical events, authors, literature, art, music, sports, weather, science, pop culture, holidays, and more. Some force the students to think about touchy subjects that question their ethics. Some are silly. Some connect with the units we are currently studying. No matter what they are writing, they are practicing critical-thinking skills, as well as writing skills.
I use journal prompts as my go-to resource when we have a little time left over or when I need my students to settle down. There's something calming about the activity. I used to have my students write three or four times per week, but I've found in recent years we haven't had as much time to devote to the activity. One of my New Year's resolutions is to have my students journal more often.
I've linked a couple of free prompts from my "A Year of Journal Prompts" bundle (which is aligned to the Common Core State Standards). You can also download a sample of the prompts for August {here}. The download doesn't have the full-page slides, but it gives you an idea of what kind of prompts I use with my students. I try to give my students 10-15 minutes to complete their responses, which means I expect them to write more than just a few sentences. My bundle contains handouts that give students more direction, but I usually just project the prompt on the board and students write in their notebooks or type on their laptops. For students who are gone, I print the page or email them a screenshot of the prompt.
Direct link to prompts:
http://www.teacherspayteachers.com/Product/A-Year-of-Journal-Writing-Prompts-Common-Core-Standards
Clip art used in images:
http://www.teacherspayteachers.com/Product/Doodle-Sketches-Bundle-of-Clip-Art-Graphics-for-Commercial-Use
Fonts used in images:
http://www.teacherspayteachers.com/Product/KG-Seven-Sixteen-Personal-Use