Visual aids are an important presentation tool that appeal to different learning styles and keep audiences engaged. The type of visual aid used depends on whether the occasion is formal, semi-formal, or informal, and may include slides, charts, or flip charts. Effective visual aids have a clear message that is easy to read and understand, with uncluttered designs featuring important points in clear letters and words. Presenters should be familiar with the equipment and practice integrating visuals, referring to them as they present rather than just displaying them. Specific techniques include keeping writing brief, properly projecting slides or transparencies, and ensuring the visual does not block the presenter.