When shooting the sequence, try to capture the same area each time. Hand-held shots work reasonably well. However using a tripod or a fixed support, such as a wall, usually improves the results.
Avoid crowds of people! Each part of the background you want to appear in the final image must be captured on at least two photos. The more picture with empty background the better. With too many people on the picture it is usually hard to get rid of them.
Take a minimum of three pictures. However, the number of photos does not determine the quality of the result. Best results are achieved when unwanted objects appear as differently as possible on each photo in the series.
The lighting should be the same for each photo. If possible with your camera model, set the aperture and shutter speed manually. This is usually the case when compact cameras are used and the same area is photographed.