Image-editing tips
Why and how do photographers process images after capture?
Photographers who used film cameras made their choices about how the image looks before the shutter was pressed. Some follow that same methodology today, either not being interested or confident to work with the pictures after capture. Advanced cameras include the ability to process Raw images in-camera, making new JPEG files.
Post-processing on a computer allows you to refine and improve, even fix some aspects, of shots. Changes to pictures broadly fall in to two categories: manipulation of the content of an image, and tonal adjustments where you lighten, darken, sharpen and enhance what is already there. Canon DPP is free to download and use, and provides the ability to enhance JPEGS and Raws. DPP reads the settings from the images, and applies them as defaults for each picture so they look the same as on the camera screen, reducing the amount of processing.
For complex changes, to specific parts of the shot, more advanced tools are helpful. Affinity Photo is a great value choice with comprehensive tools; Adobe Photoshop Elements is simple to use; full Photoshop provides almost unlimited editing. Removing the proverbial telegraph pole from your subjects head is possible with these. You might also consider Adobe Lightroom as a tool for not only fixing your photos, but also organizing and cataloguing.
The challenge for many people is knowing what to do to make a photo better. If you look at your shots and are happy with the results, then processing may not be needed. For an initial step, look at the overall brightness, and adjust that, then move on to the shadows and highlights. You might want to selectively adjust part of a photo, subtly darkening the background makes the key subject stand out more. Photoplus tutorials have great post processing tips.