From an illustrated lecture on the Origins and Traditions of Halloween to over 130 people at the Victoria & Albert Museum, my lectures and talks over the last 20 years are well researched and have included the following:

V&A: The Origins and Traditions of Halloween 
Treadwells: Wheel of the Year of one hour lectures on Samhain, Yule, Imbolc, Spring Equinox, Beltane, Summer Solstice, Lammas and Autumn Equinox, Tarot Myth & Symbolism, Venusian Witchcraft, The Five Elements, Five Witch Goddesses
House of Hackney: Moon Magic with Hekate, The Origins and Myths of the Serpent, Serpent Symbolism within the Tarot
Mystic Arts Festival: Tarot and its Symbolism, Introduction to Wicca, The Fools Journey as Sacred Theatre, Wicca & Witchcraft
York University for Interfaith: The Rise of the Teenage Witch
UK Tarot Conference: Learning Tarot
Oxon Hoath Retreat; Sacred Dance, Tarot for Wellbeing
London Frieze Art Festival; Witchcraft in the Media
I have regularly lectured locally in Kent, where I live at the Wigmore Library and several Rotary Clubs. These talks have a local flavour and have included Witch Trials of Kent, The Wheel of the Year, What is Tarot and the Origins and Traditions of Halloween.
I have also spoken at pagan moots on Tarot and the Western Esoteric Tradition, Witch Trials of Kent and the Goddess Inanna.