This step is the easier of the 4. By now you should have just about mastered the art of making simple gradients so I am not going to go into too much detail for this one.

 

Basically what we are going to do is add a spot for your content (text) to go. For this, select a rectangle shape that just about fills up the empty middle space from side to side and is not too thick. Use your gradient tool to make another gradient, making sure that the darker portion is on the top.

Now for the place were your text will be. Use your selection tool to select a large rectangle and fill it with a dark gray, slightly lighter that your bg color.

Now just give your gradient a light gray border, and your rectangle content portion a darker gray border.

I make two of these content boxes, one small and one big simple so I can have 2 sections for my page.

 

Well, there you have it. You are all done, and you have a nice interface :) I hope you enjoyed the tutorial.