Open a new canvas and with your preset rectangle tool draw out a paper (foreground closed, background: colour of choice). Convert to raster and apply any effects you want to (I used Mura Meister’s Cloud filter and a spatter brush, and a paper texture effect from Filters Unlimited).
Select all – Float – Defloat, then apply the Jeux de lignes / Entrelecemant filter (which is a freeware plugin and can be downloaded here). You will need to play with the settings to get the type of lines you want to (I used a line spacing of 28, a thickness of 1 and lowered the opacity a bit, and played with the colours to get dark blue lines).
You have a basic notepaper or index card, which you can now embellish any way you want to. Add a tube, add a crumple or a burnt edge, put some text on it, etc.
Here’s another one. I made a light green background, applied the Cloud filter, then I put a flower picture over it, and lowered the opacity. I then found a ding font with ladybugs and coloured them. Finally, I added the text.