How to set the ui design standard type?

How to set the icon type of ui design? The first method: first create a new document in ps software, open the document, find the required material, and then press the shortcut key to drag the document in. The second method: after finding the required material, click the layer and save the matting as. The third method: cut off the background material, there may be layer errors (only the background can be adjusted to pixel style). The fourth method: remove the highlight layer, adjust the brightness of the background layer, and then press the shortcut key to select white to adjust the transparency.