Make the avocado mixture:
In a small bowl, combine the beans and avocado. Mash with a fork until mostly smooth. Season to taste with lemon juice and salt.
Assemble the toast:
Spread the avocado mixture on the toasted bread and top with the garnishes of your choice, if desired.
Refrigerate leftover rinsed beans in an airtight container and eat within 4 days.
