Q: As far as practice goes, how is Breslov different from Chabad? Do they place importance on similar things? Do Breslovers use the Siddur Tehillas HaShem or a different one?
A: The most noticeable differences are  when they daven (pray) Shachris — Breslovers daven as early as possible, even with a sunrise minyan, whereas Chabadniks daven later in the morning, often not starting till after 9AM;  Chabdniks have a uniform look/wardrobe, whereas there is no dress code in Breslov, although most Breslovers do dress in a chassidic style.
Breslovers daven whatever nusach their fathers’ davened or what they learned when they returned to Judaism. Some use Tehillas Hashem, some daven Nusach Ashkenaz, most “standard” Nusach Sfard (or Sfardi for the Sfardi Breslovers).
Hope this helped.