Only send out the programme and other materials in digital form. This limits the unnecessary use of paper and allows people who need it to use assistive digital devices for reading or magnification.
Do not put publications and flyers out on tables. Only use pop-up displays and reusable visual materials. Encourage participants to share materials with each other, e.g. with QR codes. All LinkedIn profiles have a unique code that can be used as a business card.
Look into whether decorations can be borrowed, rented or otherwise reused.
Avoid all kinds of merchandise and notebooks. They often have a short lifespan and end up as waste.
Decide whether to make name badges. If so, use standard paper and holders that can be reused for other events. Ask the participants to return them at the end of the event. Give participants the opportunity either to write their own pronouns on the name badge when they arrive at the event or prepare small stickers for them in advance (e.g. she/he/them/all pronouns).