Q.Fall preparation of raised beds.
Besides removing any plant debris, is there any thing I need to do to prepare my raised garden beds for the winter? I usually don’t do anything further, and have fairly good results the next year. But could I do better?

Yes, fall clean up of plant debris is very important. The next step is to nourish the soil and improve soil tilth by putting several inches of tree leaves over the soil. Some advise chopping or running over leaves with a mower; most leaves don't need this but maple leaves are well-known to mat together creating an anaerobic environment that inhibits breakdown. Another concern is that many a butterfly chrysalis and other beneficial insects spend the winter rolled up in leaves or as eggs attached to leaves; mulching or chopping destroys these creatures. One solution to matting of maple leaves is to mix the leaves with compost. 4 inches sounds about right. So get out there and take your neighbors' leaves when they are put out for compost pick-up. Fall is also a good time to work in nutrients for correcting deficiencies and pH problems. These amendments need time to work so fall is a great time. Withhold nitrogen; it passes quickly through soil and will be gone by springtime.