There are many options to choose from, such as photo editing programs. Adobe Photoshop, Corel Painter, Paintshop Pro, GIMP.net. All functions are very similar now. With these basic photo editing tips, you can work in just about any application available.
Working with Layers in Photo Editing
The "magic" of Photoshop and its clones is the "layers" feature. This is analogous to color separations in which each of the four colors (cyan, magenta, yellow and black) are four-color printed on separate printing plates and then printed over one another to form a full-color image. Each "CMYK plate" is a four-color plane.
When you open a photo in Photoshop, it has only one layer, the background layer, and is called a flattened image. If you use the Lasso tool to sketch a tulip in a field of many flowers, then cut that tulip and paste it back into the same photo, Photoshop inserts it as a new layer, displays it in the Layers palette, and names it as Level 1
Each time you cut and paste a flower from the flower field of the photo, Photoshop creates a new layer so you can edit it, recolor it, change the shape, resize it, add a filter such as a box. Watercolor or Style from the Styles palette or a dozen other features. Only the "selected" level is affected. That way you can use different effects and filters for each layer – and a mistake on one level does not affect the other layers.
Why you should leave your original intact
The most important tip I can give you is: Never edit your originals. Always make a copy and, if possible, save this copy as a layered file, as layers can be customized and edited.
The best layered formats are PSD (Photoshop) and TIFF (Tagged Image File Format). All popular photo editing programs store either under or under in one of these two formats.
Why not save pictures as JPGs? Because JPG is a lossy format, the image is compressed, creating smaller files (for applications with limited resources such as e-mail and mobile phones). Each time you save it, the quality of the picture deteriorates and no levels are supported.
The other image formats such as BMP, GIF, PHG, EPS and more are not suitable "working" formats. In other words, they are not suitable for editing images.
NOTE: RAW and DNG come in a very different class of formats that are generally used by professional photographers and are not supported by all phones, cameras, or programs.  Resizing photos without losing image quality
Shrinking or shrinking images is not a problem. The resizing to ruins everything. As you try to enlarge images, the pixels explode and create fuzzy halos around you. This is called photo-compression noise or pixeling.
To avoid this, never enlarge without adjusting the pixels to be compensated. For example, if you have a 4 x 5-inch photo at 600 pixels per inch (or 2400 x 3000 pixels), you can increase the photo to 8 x 10 if you reduce pixels per inch to 300 (note that the pixels are still present) 2400×3000) and does not lose image quality. If you zoom in at 8×10 and leave the ppi at 600, the image will blur any time you try to resize it without lowering the ppi.
It is important to distinguish resizing from a feature in Adobe Photoshop (and some other editing programs) called "resampling."
The paragraph above is an example of resizing; that is, the number of pixels in the image does not change and; Therefore, the picture quality is maintained. Resampling alters the image by adding more pixels (upsampling) or subtracting (downsampling). This means adding and removing information and details about your image. Unfortunately, this is not a precise process. That's why Photoshop offers three resampling options: Bicubic, Bilinear or Nearest Neighbor. There is no "right way" or "right answer" to this process. You can just experiment and save the picture with the best results.
How to Remove Busy Backgrounds
Cutting out unwanted wallpapers is always a challenge. Using the Polygonal Lasso tool, you can select the object in the foreground, then invert the image to make the background the active layer, and then press the Delete key. You can also cut and paste the image into a new layer and select a special effect to fill in the background. Gaussian blur or motion blur, or choose a suitable filter.
Another option is to use the pen tool to sketch the object and create a clipping path. If the object is completely outlined, hold down the Ctrl key while clicking on the vector mask in the Layers palette. The selection frame surrounds the selected area. Move the cursor to the background layer, flip the image over and press the Delete key. Both options give the same results, and both are quite easy to do. It is therefore only a matter of personal preference.
You can also use the wand for pictures with different light and dark areas. This can be difficult and often selects areas that you do not want to select. You can, however, use it for large areas and then fine tune it with the lasso.
How to Use the Clone Stamp for Smoothing and Polishing Surfaces
The Clone Stamp tool, not to be confused with the Blur or Blur tool, is all about the right brush style, brush size, and brush position. The brush should be smaller than the eraser head of a pen (size 40 for a 8×10 photo at 300 ppi is good), round and slightly blurry. The position should be as close as possible to the stamped area.
Position the brush on the surface you want to clone (for example, a smooth, flawless part of the face). Press the Alt key and click once with the mouse. Move the tool over a bad area and click again. The blemish disappears.
If you want it to look natural and uniform, stamp the tool in a clean spot just above, below or next to the blemish. Otherwise the skin tones will fluctuate too much and the results will look "stamped and stained". In our example, only the spots and freckles are removed, but an image adjustment feature such as skin smoothing is required to more evenly blend the cloned areas.  How to Rescue Blurred, Blurred Images
You can use a sharpener / sharpener filter for this operation. Note, however, that the image becomes grainy every time it is used, resembling sandpaper. This is not necessarily a bad thing if you like "artistic" photos. Most programs even offer multiple "Grain" filters as part of the special effects package.
You can also use one of the many Artistic, Brush, or Stylize filters that make the photo look like a painting. Based on how blurry the original image is and how much you really want to keep that particular image, a "painted" filter can enhance the original photo.
Learn More by Researching and Performing
Basic tips to learn more about photo editing is as easy as exploring and playing around with your software. For example, do you ever notice the purple rim around the objects in your pictures? It's called Purple Fringe and is now easy to correct. The removal of chromatic aberrations (caused by distortion of the lens), backlighting, and a variety of corrections such as barrels, fisheye, depth of field, and pincushion can now be easily repaired. Browse through the photo editing program of your choice to find the features to fix these errors.