Poly, Tru Oil, Formbys Tung Oil mix, Shellac, rendered fat and bees wax all work. You will get good and bad points about each. Personal preference is what its all aboout. All will work for common "joe's" just fine. Romance plays a part for some guys. They may want all natural, or they want what the ol' timers used, or one cost more than the other and so on. The best type will never be settled. Your best bet is to simply pick one and learn about it prior to applying. Some need a fresh coat each year, or several times a year, some never need to be touched again. Some stink and some smell MMMMMM good! Warm bee's wax makes me hungry everytime!
it does seem there are numerous finishes that work well. and many folks have a favorite. or sometimes just a matter of convenience(what ya got on hand versus buying something specifically for yr bow)
used tru oil just once, on a rawhide backed bow. cuz i wanted to protect that rawhide well. dont like the shiny finish but it can be eliminated with some 0000 steel wool. made a mixture of bees wax and walnut oil i like quite well. apply it as mentioned previously. warm it, rub and rub, heat lightly with a hair dryer. i keep applying and rubbing till the wood wont absorb any more. the first bow i used this on was done about two yrs ago and is still holding...
recently got in a trade, some bear grease. dude, that bear grease really brings out the color/grain in osage and some of my arrow wood too! liking it lots. but not easy to procure for some.
in fact, josh(gun doc) stopped by bow class last nite(nice to meet ya josh!) and he was talking about using bear grease on a eastern red cedar bow and that he found it had "cured" the wood in such a way that it noticeably improved the performance of the bow. might ask him for more details on that.