The title for each field in a form shows up next to the field itself, but the instructions show up above them, pretty close to the previous field.
This makes my eyes think that these instructions go with the previous field, and then I'm confused because the context is wrong.

Here, highlighted a field and it's instructions:

I think that putting the field title next to the instructions would help:

(Update: I think this is only about Settings forms, which use appendRemarkupInstructions for field instructions)
Update2: the controlInstructions field from EditEngine's EditField is also rendered as RemarkupInstructions above the field, although caption field from Control does better visual work.