Helpful Tips
This option works best when the subject or subjects take up the majority of the photograph and a lot of detail is visible.
Professionally composed portraits usually make the best paintings.
Choose photos that a tell a story or have personal meaning (i.e., a wedding photo, looking off into the distance, some sort of action, or merely an introspective look).
Avoid photos of groups of people unless it is shot with excellent lighting and it is a high resolution photo.
Simply put, the more poised the subject is the better.
For landscapes, as with most traditional oil paintings, fine details are often muted or implied therefore more attention to detail may be given to some areas over others. With that in mind there should be something in the original photo which draws the eye or be the main subject matter. It should also have enough details which can be easily recognizable once it is painted.
Please note the oil painting effect is not recommended for reproductions of original artwork since it is meant to make a photograph look like a painting and not a painting look like a painting.