First, allow a day or so between your first viewing and the final editing to allow that first rush of enthusiasm to fade. Forget about it a little, allow time to break a little bit of the bond that formed between you and the mental image so you can look at the actual image afresh.
Now, when your blood has cooled, look at again.
Does the picture have close to the impact you want, is the content all there, is there enough detail, is there enough exposure so that you can work with it? If so, or even if just possibly so, then break down your assessment of the image into small measurable chunks, where you look at specific items and decide whether items that seem 'wrong' should be or can be changed. You need specifics here to keep you on task and away from falling in love with the image in your mind again. Deal with the image on your screen.
Sometimes, you actually may have to start some of the post-processing to decide whether it is worthwhile to go on. For example, if there is considerable perspective distortion, correcting this may remove too much of the structures being photographed to allow a satisfactory result. Or when a shadow must be lightened a bit, the resultant color noise may be too much to be tolerated. There is no harm in taking a step or two just to evaluate the situation.
These are some of the questions I ask myself when I look at a picture to decide what items need to be considered in a post-processing workflow.
Are there bright areas of light or color that draw a viewer's eye from the real object of interest?
Are there one or more obvious centers of visual interest where a viewer's can settle?
Is(are) the center(s) of interest - the main subject(s) - well placed within the frame and does the placement relate well to the rest of the content so that any viewer's eye is drawn to, rather than away?
Is there excess space that pulls the eye away and drains any tension or drama from the picture?
Is there space that gives some weight to an important part of an image?
Is there enough space so that nothing feels cramped or cut off?
If the subject is a person or a face and his/her placement in the frame is asymmetric, does the asymmetry make sense to the eye?
Are there geometric issues? e.g. are the horizontals and verticals correct, and is that important or as you want them?
Is the skin color 'natural' to the subject?
Are there little off-tints in the skin? (look at the sides of the nose and under the chin where these lurk.)
Is there a bluish tint to the skin or the whites of the eyes? (Even with a custom white balance, this is all too common in portraits taken outdoors. Try adding a warming photo filter and see how this looks.)
Is the color or tonality appropriate for the content? Saturation or lack of it? Correct hues, white balance?
Does the color make the point that you want?
Is the sharpness or lack of sharpness appropriate?
Is everything that should be in focus and sharp, actually so?
In the reverse, is there so much depth of field, so much in focus that attention is drawn away from the real object of interest?
Are there individual small defects -points of motion, dirt on the lens/sensor, out-of-focus spots that hurt the image, unduly bright areas that draw the eye?
After doing this kind of image evaluation for a while, one doesn't need to dwell specifically on questions and the evaluation will become unscripted and automatic.
Nothing is wrong per se if it creates the impression that you want to make.
Something is wrong if it gets between the viewer and her/his appreciation of the image.