I find that it would be useful to implement an "Instructions" box, whether it's given as an option for each Custom Form or as a Custom Field Type so that we can place them into the custom forms that we want instructions for. Currently, the best way to do this in the system is create a text area and set logic to disable it (to avoid end users changing the instructions).
To add onto it, some formatting options would be helpful: bold, italics, bullet points, link/hyperlink attachments, color coded (to bring attention to the instructions). I also think it may be helpful to "wrap" the size of the text box around the amount of text that exists. Many users won't read the whole instructions if the box isn't fully expanded, or if they have to expand the box themselves.