Your overhead projector might be put on a trolley: it can be pushed into a corner when not in use and remain accessible. The ideal position for an overhead projector however, is directly on or even sunk into your desk on your right. The image is projected over your right shoulder. This can be on a projection screen or just on a white (painted) wall.

So you keep facing your class; it is easy to write or draw (with washable ink) on the transparency or to cover some parts not being dealt with at that particular moment. You remain in eye contact with the students and monitor the level of engagement.

This work situation is especially useful for new teachers, who may lose control of their class just at the moment they are trying to put a good explanation across.

Ensure that the transparencies, including your self-designed ones, are arranged in the correct sequence and within easy reach for use.

Use an overhead projector with a strong lamp: 250 watts was normal but now most schools purchase 400 watt projectors and this is really recommended. They provide greater contrast, deeper colours and text is more legible. Presentations are much more vivid and even remain visible in sunlight.