could I (a skilled user) implement your design exactly as you have presented it working only from your designs and without having to make decisions myself?In other words: does it tell me everything I need to know?
Size, font, location, colours, macros, formulae. The whole banana. In enough detail.
It's fine to use more than one sheet of paper for each page. You might want one for the GUI and one for formulas for a spreadsheet. You might need another form macros. For a newsletter you may need one for layout and one for style.
The key is: is there enough detail (through annotations) for me to be able to produce it.
Here's one that someone, let's call her "Grace", made earlier.
It's *just* for the GUI - the layout of the sheet. The detail's OK - but she now needs to go on and get the details of the size for the boxes (by right clicking on her sheet she's designed and getting properties and the size tab), the width of the lines, the colour of the lines and the colour (a bright yellow) of the button.
To define the colour it'd be best to use a quantitative method - like using the RGB. You should be able to find a way of doing this (ask if you can't). In this case you can go to the lines/colors tab and go to more colors and you should be able to get the RGB from there: