Use a tripod to keep the camera rigid. Invest in a good steady but lightweight tripod such as carbon fiber one. Manfrotto if you like clips or Gitzo if you prefer rotational twist on the legs. Next a great ball head. I prefer Really Right Stuff products for this or Arca Swiss monoball 2. Best to go into a good local camera store for help with deciding on what you need based on your camera and lens weight, as well as your height. B&H in NY or Hunts in the Boston area.Abstraction
Use a shutter release. Pressing the shutter will cause vibrations than reduce the sharpness of your photo. Use a remote – wired or remote – switch. Or use your camera’s self-timer with a short delay such as 2 seconds.Gloucester Fireworks
Mirror lock up to reduce the vibration from the movement of the camera’s mirror (if it has one) when the shutter releases. This presents more of a problem is the shutter speed is less than 1/30 second.
Most cameras have a sharpest aperture and it’s not at any extreme f/stop; that is when wide open due to aberration or stopped down due to diffraction. F/8 to f/11 is usually a safe bet.Youth
For a moving subject, choose the shutter speed (in Manual or Shutter Priority) that is high enough to freeze the subject movement. This may require an increase in the ISO.Three Bears fishing