When selecting ripe avocados, first you are looking for darker green color with some wrinkles but not deep wrinkles. So don't pick lighter green avocados or ones with deep wrinkles. Also, try to get avocados that have the little stem still attached. Second step is to pick it up and give it a gentle squeeze. A ripe avocado yields when you gently press it. If it yields too easily, the avocado is over-ripe. If it doesn't yield at all, it is unripe.