Tolkien spent in Oxford many years of his life, both as a student and as a Professor. Between the early 1930s and late 1949 he was also a member of the Inklings, an informal literary discussion group associated with the University of Oxford (many of the members were professors of the University). Is it possible that in their discussions they also talked about their books, receiving suggestions and support during the composition. 

Many real places in Oxford were used as an inspiration for places (and names) in Middle-Earth: the inn "Green Dragon" in Hobbiton shares the name with the one located in St Aldates; "The Prancing Pony" in Bree was originally called "The White Horse", a famous pub in Oxford where the Inklings met; the "Golden Perch", where one of the main characters, the hobbit Pippin, wanted to taste the best beer of the East reminds of "The Perch" in Binsey, just upstream from Oxford.