First, begin by cleaning the image. Use a cleaning tool to eliminate spots, dust and other imperfections in the image. This can help improve the clarity and sharpness of the image, which will make the editing process easier.

Then, use a color correction tool to adjust the saturation, tone and brightness of the image. This can help improve the colors and make the image more attractive.

Once you have cleaned and corrected the colors in the image, you can begin to work on the details of the portrait. Use a sharpness tool to improve the sharpness of the outlines of the face and eyes. You can also use a blurring tool to soften the areas of the image that are too contrasting or noisy.

Finally, use a touch-up tool to smooth out skin imperfections and remove fine lines and wrinkles. You can also adjust the brightness and contrast of the image to give a more uniform and natural look.

When working with a low-resolution image, it is important to remember that you might not be able to obtain an image quality that is as good as you want. Nevertheless, by using the right tools and the right techniques, you can improve the quality of the image considerably and obtain a successful edited portrait.

In conclusion, editing a portrait using a low-resolution image might be challenging, but it is not impossible. By using the right tools and the right techniques, you can improve the quality of the image and obtain a satisfactory result. Remember always to be patient and to experiment with different techniques until your find what is best suited to your picture.