To get the banner design style above, see steps below – CorelDraw. I created a similar design for a print advert design,see it here
1. Create/draw your object(s), you may use same colours.
3. Apply a shadow to the top object, ‘bring to front’ so that its on top of the other object.
4. Select ‘arrange’ from the menu bar and select ‘break drop shadow apart’. Then rotate it.
5. Place the shadow in the object below using the ‘power clip’ tool
You should have something like this