Any tips for a good bow/arrow combo?
bow: slime,slime and enchanted sting. pile on the redstone.
arrow: feather fletching always and slime rods for range and paper when needing an extra buffslot.
arrowheads depending on what properties you want. thaum for extra buffslot (paired with a paper rod this gives a whooping 5 slots), cactus for decent dps sniper shots, and the manyullyn stuff for that ultra heavy boss slayer arrow set (overloaded with quarts ofc).
cactus tipped sniper arrows tend to get lost, so don't bother quartsing them up much, just a single piece per arrow for half a heart bonus, and a single blazepowder to roast your dinner with when on the move.
For killing difficult bosses it seems that quarts is the way to go, altho you can add an enderpearl and obsidian block for beheading as well for hunting those pesky witherskellies. Don't bother with fire tho, not worth it with bosses since they are often immune annyhow. a wither bone may also be good, havent tested that myself, but if it works as advertized then getting health from ranged kills is very very powerful.