There are times when I'm walking around enjoying the scenery and occasionally taking what I think are interesting photographs around town and I forget to compose correctly. This is normally not noticed until I review them later as I tend not to look at each shot when taken.
This is a different shooting mode than when I really want something special. Then the histogram is reviewed and for images with strong contrast several exposures may be taken. And if tripod is available it will be used.
The above image is the final edited version that I wanted but failed to capture correctly.
Part of the problem is that I wear glasses and sometimes I don't remove them when looking in the camera view finder. I do when the image is critical but for shoot and grab shots I tend to place viewfinder only on the glass face and if I don't line up correctly the image is off centre to what I see.
If you have taken several photos then there may be parts in others that you can use to correct test perfect sections.
In the 3 photos combined below, the far left image is the one I wanted (#1) but as you can see, it's missing parts like the feet and sidewalk. The 2 other photos (middle #2 and right #3) are ones I used to fill in missing sections and cover parts that needed to be removed. The big problem with the other photographs is that they are from different angles and perspectives and therefore, a direct overlay to match parts will not work. You will need to stretch, twist and rotate a little to make the parts fit.
In the next composite photo below with the main image, I extracted the parts of each section that was used to reconstruct the final photograph.
Image #1 provides a good frame-work (base layer) for the whole of photo, except I wanted the lady in image #2
Image #2 was cut and placed on a separate layer and set to difference mode to make it easier to see when frame matches as it all turns black. I needed her bottom feet from another image (#3) to finish off her legs.
There was still the problem of the missing parts of the steps from part #2 which was added by image #4.
Rather than placing a whole copy of another image on top and using masking for desired parts and moving around, I recommend only cutting out the main parts from another file and copying to the working file. The reason for this is that when you zoom in on a large image to examine the fit, the handles are no longer available to use for positioning as these are at the edges of image. By only using a cropped parts, the handles for positioning are now just outside the smaller part and available for use even when zoomed in.
This is a lot of work and not for everyone. It would be easier to retake the photograph, if possible, but if you're on vacation or it's an impromptu moment, it may not be possible. This process allows you to get the photograph that you wanted but somehow missed.
I do realize that I need to be more careful when using glasses and maybe a monocle for the other eye would work. This is one advantage that EV viewfinders on back of camera work well for people with glasses.