Prospective teachers often draw on their own experiences with writing as they envision and plan for future writing instruction. Rather than analyzing the types and topics of writing that teacher candidates engaged in as K-16 students, this study inquired into the mediational means shaping their writing processes. The teacher candidates in this study partnered with local high school students to blog about their varied in- and out-of-school experiences with writing. An analysis of these blogs revealed that three overarching mediational means--rules, time, and purpose--had either restrictive or enabling effects on participants' writing. Findings from this study suggest that the value students attach to writing is a function of the mediational means that shape the experience. This study suggests that as literacy teachers prepare for writing instruction, they should pay particular attention to the restrictive and enabling effects of the various mediational means employed.