Even if you only have a few beans, make sure you pick them daily. The more you pick the beans, the more the plant will produce. The converse is also true; if you stop picking beans, your plant will stop producing.
This good advice can be applied to many other vegetables, as well. Okra is the first to come to mind.
Growing Green Beans
Storing Green Beans?
Using Green Tomatoes
Growing Vanilla
Harvesting Common Garden Vegetables
Growing Beans (Bush and Pole)
Flavored Greens Beans