Not sure there's a way to make them more interesting. But I try to play them in various ways. In other words, not always play the same scale in the same key. I usually pick a key and play an open and closed version of the scale to start off, then play backwards and forwards a couple of times. I play a vertical or horizontal pattern. And I try to say the number of each note I hit (that especially halps with pentatonics, I've found). Then I'll work minor the same way, then the pentatonic scales. Anyway, it can be mind-numbing to do more than 10 or 15 minutes of this at one sitting.
Another thing I've been doing lately is adding some of the scales to solos I'm practicing. I have not perfected this yet, but it makes the scales a little more interesting and I'm hoping I'm developing a little more ease with moving around the fingerboard.