Some easy-to-follow advice:

• Start using the Auto exposure mode of your camera, then switch to Manual to shoot in these exact same conditions (of course, the ambient light must not change, so don’t wait too much and avoid times when light is changing quickly -sunset, storms, etc.).
• Use a tripod, but if there are not too many objects in the front of the subject don’t worry about computing the exxact optimcal center of the camera+lens.
• Disable the autofocus after setting the focus correctly and maintin this focus position on all the images.
• Do not keep the Auto White Balance on the camera. Instead, select one single WB mode that will be used on all images.
• If you do a horizontal panorama, shoot in vertical (portrait) orientation (to increase the usable surface and to improve the final resolution).
• Make sure that you have a wide cross-image section to ease the merging process. The merging software package will thank you.