Here a few instructions on creating a cool flower background in Illustrator.
Open a new document. Draw a square and colour it.
Choose the Mesh tool to add a light to the background.
Then choose the pencil tool and draw a few lines. Use the Brush tool and add some flowers.
Now, choose the pen tool.
Create two lines and blend them.
This is what we will get.
Also try to add a few more flower symbols.
See the result.