You may want to use a tripod. If not at least use a monopod.
Your settings may affect the smoothness of the footage as well.
For eg. I am shooting in 24fps, and my shutter speed, I will keep at 1/50.
If you are shooting at 30fps, your shutter should be at 1/60.
If you use a faster shutter speed than the fps, you may get some choppy motion. The tip for shutter speed is 2 x the frame rate.
Try shooting a running water or fountain or water fall using different shutter speed and frame rate combination, and you will learn why.
Shooting at a larger aperture number will have a sharper image all round. If you are shooting handheld, and moving around, shooting with a bigger f-stop can ensure most of your frame are in focus and sharp. Use a tripod if you want to play with lower f-stop number for pulling focus effect. Use ND filter to cut down the light instead of changing shutter speed when using lower f-stop number. (refer to previous paragraph if you are asking why)
Use MF if possible, you can prefocus using viewfinder or if you have to use AF, set to single point focusing. 3D focusing usually too smart for me. They always focus on the girl behind my wife...
Lens or camera with image stabilizer can help a lot as well, if you are shooting handheld. Invest in a good lens.
Last, next time if you want to ask questions, you need to describe your issue with a lot more details... what camera and lens you using? manual exposure setting, focus setting??? I want to try to help, but all I can give you is general tips. May not solve your problem.
Cheer, enjoy shooting, shoot more then you can learn.