My contractor-style tablesaw spewed sawdust everywhere until I enclosed the base by covering all the openings with 1/4-in. MDF panels. First, I added two aluminum angle rails so the collection box slopes toward the dust port in the back panel. Then I screwed on the MDF panels.
I made two custom-fit panels to cover the open back, one for 45-degree cuts and another for 90-degrees cuts, because those are the most common blade positions I use. These panels rest on the lip at the back of the opening and simply slide in and out of place. I marked them for cutting by measuring around the motor mount and belt guard.