If the lens has a smudge it can easily show up on several pictures and can look like an anomaly, so look for that sign. Try to always keep your lens spotless. These can appear as a vortex or other ghostly images if left to dangle free from the camera. If your thumb or finger is in the way of the lens it can cause this same effect. Make sure long hair is tied back.
Hair can also appear as a ghostly anomaly.
Strains of hair can look like orbs in motion as well as ghost energy. Completely avoid taking photos when conditions are windy, foggy, rainy, dusty and where it's snowing or when moisture is in the air. All of these conditions can cause images to appear that look exactly like orbs and ghostly anomalies. In cold weather make sure your breath is not affecting the photo results. To avoid this do not take photos in the direction of the sun.