This is a poster I did for a local Urban Farming group advertising their Big Picnic Bash. It pretty much speaks for itself. Lists all the need-to-know info, and then some.
Posters like this can be a challenge where you’re to include a lot of text. When that’s the case I try to include very little, or no imagery, to avoid making it busier. Just playing with different fonts and colours, can often get the job done. Left the margins white for printing on a budget as it’s a non-profit group.