Easy but impressive......

Open Illustrator and create a new file with any size you want.

Step 1:

Using Pen Tool (P) to draw a curve, after that duplicate this curve and combine them in a group like:

Step 2:

Go to Object -> Blend -> Blend Options and choose 20 for Specified Steps. You will get this:



Step 3: Duplicated layer in step 2 and arrange them by different angel and you have:

Step 4: Fill color and this is my work