In this video Phil Davis explains how to transfer a photograph to your support be it a canvas, a board, or paper. In the film the grid method is employed. However, that is not the only way to achieve good results. Instead of drawing a grid on your reference photo you can print or draw the grid onto a transparent sheet or overhead transparency.
You can place the transparent grid sheet over any original you want to work from without spoiling it. Afterwards you continue as demonstrated in the film. In any case it is important to attach the sheet firmly to your template using a removable adhesive to stop it from slipping.
Your transfer will be the more detailed the finer your grid. Always make sure to have the same number of squares on the grids both on the original and on your canvas or board. Otherwise you may fail to transfer parts of the original to your support. The size of the squares on your support is determined by the relative sizes of your support and the original.
If you want to transfer a 10x15cm original to a 20x30cm support the squares on the support must be twice the size of the squares on the original. Therefore the squares on a 40x60cm support must be four times the size of the original grid squares.
There are alternative methods available to transfer an original drawing to your canvas or board which also help you to save time. These will be dealt with in future posts covering projection and tracing.