Our best and most accurate description of gravity we have of course is Einstein's GR and curved spacetime. An excellent analogy that gives us a mental picture of this is the stretched rubber sheet analogy. Although an excellent analogy, it needs to be said that all analogies are constructed to help visualise how gravity works, and more Importantly that they all have limitations in what they are describing. Here is another I found that helps explain "How gravity makes things fall" What do you think? The video is 4 minutes long.