Use consistent language when giving instructions for similar assignments, that way students don't have to analyze the information again in a new way.
Also, avoid too much bold and italic, as too much emphasis equals no emphasis at all.
The importance of consistency in style and language is that it helps students -- they need visual cues and expected formulas so they can understand how to navigate the course and not have too many surprises. The most enterprising students will ask if there is confusion, but some will just drop off.
