most professional and qualitative will be to insert a face into a collage using Adobe Photoshop. Download the free version of the program (will work 30 days) on the official website of Adobe.com.
Collage search can be done on a number of both paid and free photo stocks. Download collage from Shutterstock.com (paid templates) or Olik.ru (free). The most common image template formats are: tiff, png, psd.
easiest thing will be to work with collage template in psd format. It is split into layers that can be removed, moved one under the other; resize elements on them, erase parts of the parts.
Add a photo to the file with collage. To do this, open the photo and collage files in “Photoshop” in different windows (“Open” from the “File” menu). Drag the photo with the Move tool (Black Arrow label on the toolbar) to the template window. It will automatically move to the created collage layer.
From the photo you need to cut your own face. To do this, use the Magnetic Lasso tool (Magnetic Lasso). Circulate the outline of the head, capturing pixels close in color. If you use Magnetic Lasso to highlight a larger or smaller area than you need, you can add (reduce) an area using the Lasso tool.
Trim the extra part of the photo. Invert the selection (Selection, Inversion). You can delete an unnecessary part of a photo by Eraser or trimming tools.
Resize your face using the Free Transformation tool. Hold Shift to preserve linear proportions.