Take picnic packaging home to avoid litter, and use an eco cooler bag to stop salads wilting in the sun (add dressing before serving). Choose reusable cloth napkins over paper ones, and try not to make more food than you need, to avoid waste. Try these vegan cucumber sandwiches (Full of Plants).
Keep dogs away (they’re near your level!) from cooked bones, crusty bread, chocolate, beer, salt fizzy drinks etc (same for birds and wildfowl – buttered bread can smear on feathers, affecting waterproofing/insulation.
Heima sells enamel picnic cups, plates and kettles (like the old red-rimmed white dishes you find in hardware stores). Take your own reusable cutlery and take broken glass and ring-pulls home.
Use a personal ashtray to safely stub out butts, to prevent wildfires.
Boycott beer brands that wrap in plastic rings (invisible in water, so harm wildlife) and don’t release balloons.
Marmax Products makes colourful picnic benches made from recycled plastic milk bottles. They are waterproof and won’t rot (just wash with water to last 25 years). In wheelchair-friendly options too.
Karten picnic tables (also for children) are made from sturdy cardboard and biodegrade after use (they also make cardboard tents and chairs!) These tables are strong enough for four people (as long as you don’t jump on them!)