Normally we would play scales using quarter notes. Nice, even quarter notes, with even dynamics. It's important to be able to get this right before we start changing it up.
Let's look at an A major scale, played 2 octaves apart.
Changing it up
Now, to make things interesting and keep challenging yourself, try throwing in some different rhythms to your scales. Instead of just using quarter notes, try some alternate phrasing. Here are some examples:
Here we're playing the 2nd and 3rd as eight notes, and then a half note to end. Then we repeat that rhythm as we descend.
In this example, we use a syncopated rhythm, with an eighth notes to start the scale and then quarter notes the rest of the way.
Here we use a combination on dotted quarter notes and eighth notes for a more interesting rhythm.
We can also change up the time signature. In this example we're playing in 6/8, and we've added 2 notes at the end of the scale to complete the phrasing.
Try these in all keys and with all the scales you're practising. You will surely find them more engaging than the traditional quarter note scale. And try your own rhythms, play around and see what you can come up with.
Another tip: load up your DAW and record/programme a beat to play to. This definitely feels more musical than playing along to a metronome.
Scales don't have to be boring. Improvise, try different rhythms and beats, and before long you'll find you're actually enjoy practising them.