Like the major scale, it is important to be comfortable with the Blues scale in every key. The following example demonstrates the Blues scale moving up chromatically through all the keys. Once again, memorise each one and then connect them together until you can play the whole example smoothly and evenly without looking at the notation. Then try reversing the order of the keys (moving down chromatically).
Once you are comfortable with the scales themselves, try inventing a short riff from the Blues scale in one key and then playing the riff in all keys as shown in the following example. If you have trouble with this, memorise all the scale degrees of the riff before transposing it. The riff shown here begins on the flattened 7th degree of the key.