Though Anglo-Saxon culture was never "pre-agricultural," there are some animistic elements of folk customs that have survived in modified form down to the present day. Im sure there must be some elsewhere, but I've primarily researched English and Scottish traditions. Feel free to add your own research here.
1. Apple Wassails and Wassailing songs generally, preserve a very similar structure to the ritual feasting described by late Norse sources. The ritual goes something like this: sing and shout various positive wishes about someone (human or other being), starting with the general wish that they "was hail," meaning 'be whole/holy/hale/healthy (Imperative).' A "bowl" or large goblet of various or specific alcoholic beverages (cider for apple trees, mead, wine or beer in other cases) is then taken and some is drunk by each in turn. Each person also pours out some of the drink and shouts to the health of someone.Often the chant is "Wassail! Drink hale!" This can be poured at the roots of apple trees (or theoretically any tree) or just onto the ground. This represents the portion that the toasted person would drink. I believe Norse literature calls this a symbel.
2. Another tradition is the Horn Dance of the village of Abbots Bromley, England. The "horns" are elk antlers carbon dated to around AD 1050 and the dance was written about from the 1200's. The dance is still being performed every year by the surviving descendants of the group that performed it from at least the 1500's. The current music that the original group performs sucks, imo and the outfits are quite sanitized by the generations of christian sensibilities. However, the theoretical original song for the dance gives an entirely different feel and some have reinterpreted the dance to look more pagan, which I mainly approve of. I interpret this dance to be a half-christianized Heathen dance that honors prey animals and ensures a good hunt.
3. The recreated tradition of the Straw Bear in Whittlesey, England is strikingly similar to the Lowland Scottish tradition of the Burry Man. Both are men covered in plant material who parade around town(s) and are treated well by the townsfolk. The Burry Man tradition has more continuity and more details. He is said to have the purpose of giving good luck in various endeavors, including fishing. The Straw Bear has a double made of the same straw, which is burned. This is the only ritualistic detail that modern recreations have preserved, since that was the only detail, save the costume and name, that was written about. Tantalizing clues as to the purpose may come from the song "John Barleycorn Must Die." The Burry Man on the other hand, represents the wild burdock plant, which has a starchy, edible root.
4. The May Pole tradition spans numerous countries, but I believe originates solely in historic or prehistoricly Germanic areas. Various traditions have emerged, with slightly different details. One regional tradition (at the least) has people climb to the top to get things; some burn the pole each year and cut a new tree; some weave ribbons around it. I think this links directly to sacred tree symbolism (particularly Odin's climbing of Yggdrasil and the "trees of life" that bear the golden apples keeping the gods alive), as well as the Yule log.
Anyone have things to add? Different interpretations? Other traditions?