I have never believed that some people are creative and others aren't. I do, however, feel that creativity is akin to a muscle, and muscles that aren't exercised atrophy. Now, if one hasn't worked on this before, it can seem a little daunting, but keep in mind creative thinking and acting is often done in small ways. We could apply this to our practicing by doing our routine ( if we have one) backwards, or out of the usual order. Another simple way to get us out of our usual patterns would be to change the placement of components of the drum set. Ride cymbal on the right, crash on the left? Reverse them! I guarantee your usual movements around the cymbals will sound different, and it will take some thought and physical shifts to do them the way you usually do! I recently set up a five piece kit at my practice space and, borrowing an idea I got from Max Roach, reversed the order of the tom mounted toms, like so…..
Once again, habits are broken and "regular" tom patterns take on a whole new challenge.
Other possibilities like changing dynamics, rhythmic grids, and tempos of anything I've gone on about at length before, but what about playing with two different utensils in your hands? Again, a beat you played using two sticks will sound VERY different with a stick & a brush, a mallet & your hand, etc. Along similar lines is using different parts of the drum set than we normally do as send sources. Ever played an idea using the shell of one of the drums? How about the cymbal stand? Moving the snares on and off? These sort of things can be very fun to explore and come in handy, especially in more open/free music settings.
Another really good way to begin a session at the drums is to play something, anything, at the drums and try to make a short composition out of it. By short, I mean it can be a minute long, if you like. The idea, is to take the first thing you played and then develop it so it has a beginning, middle and end. The main thing is not to judge the thing you played, just to work with it. I got this idea from Ari Hoenig, and it can be a great help to developing improvisational skills.
The whole point is, always ask yourself, " How could this be different/changed/varied"? As you make a habit of this, creative thinking and action will come automatically.
Have fun on your creative journey!