A wide angle lens might help, but do not angle the lens upwards - a shot up the nostrils is not very pleasing.

While not a shooting technique, you could increase the breast size while editing the picture.

Also poses, where the model leans slightly towards the photographer help, and the model should push out her breasts (make a hollow back). Ask your model to present her breasts - you as the photographer have to help her find a good pose.

If the model is dressed you can use clothing to emphasize breast size: clothing should be tight fitting - some checkered patterns emohasize the breasts. If you can print on clothing you could print a pattern where the squares where the breasts will be are slightly larger than elsewhere - this will look like the breasts pull at the fabric.

A wide angle lens might help, but do not angle the lens upwards - a shot up the nostrils is not very pleasing.

While not a shooting technique, you could increase the bosom size while editing the picture.

Also poses, where the model leans slightly towards the photographer help, and the model should push out her bosom (make a hollow back). Ask your model to present her bosom - you as the photographer have to help her find a good pose.

If the model is dressed you can use clothing to emphasize bosom size: clothing should be tight fitting - some checkered patterns emohasize the bosom. If you can print on clothing you could print a pattern where the squares where the bosom will be are slightly larger than elsewhere - this will look like the bosom is pulling at the fabric.