Try 1/8-1/4 sec with moderate telephoto, like 50mm and up (70-200 zoom is good) . You can use 1/15, but then you really have to move the camera a little faster. Use small fluid movements, not jerky. Trigger shutter same time as you start movement, it's almost instantaneous. If you use wider lens, try at 1/4 of sec to ensure blur is transmitted. If on long end, say 200mm, movement is more erratic due to hand and body movement, slight movement produces greater and exaggerated effects, so be judicious. Now it's up to you to find the right subject matter!
Good luck!!
JR