Use the Flatted Fifth in Your Blues Scale Licks
One great way to use the flatted fifth is to approach it from below, ascending from the fourth (Example 4). Likewise, you can approach it from above by descending from the fifth as shown in the first measure of Example 5. Another great way to use this scale is by playing licks that move through the added note, essentially using it as a passing tone between the fourth and fifth degrees, as shown in Example 6.
Excerpted from Acoustic Rock Essentials: Soloing with the Blues Scale