Obviously practicing scales progressions can get monotonous and utterly boring. So, I spent a lot of time playing over songs that I really liked, learning what the artist did, and then doing it myself, but mixing the combinations up a bit. Take a few of your favorite artists and pay attention to what they do. A lot can be learned from that alone.
I spent a lot of time listening to some of the blues legends and, most notably SRV. I learned their chops and licks and then elaborated on them a bit. So often I would watch what they would do and say,"Wow, I didn't know that you could go there at that point", or "I didn't know you could bridge those two progressions together." Once you start putting the pieces together, you will be off! :D
It is worth noting that improvising is a difficult art that even the greatest musicians can struggle with. It's a real challenge to build something that is not just a debacle of notes, but melodic, emotional, and enjoyable to hear. I also remind myself that playing a few well timed and precise notes can say a lot more than just ripping through the scales as fast as you can. Not sure if this helped, but it is kind of how I learned it. :D
Oh yeah, and practice, practice, practice! :lol: