The interesting thing about Bifur and Bofur is that they are Dwarves who clearly suffer from early authorial editing. In John Rateliff's history of The Hobbit, the author identifies an early instance (the so-called 'Bladorthin manuscript') where Bifur, Bofur and Bombur are described as Thorin Oakenshield's "attendants", which Rateliff infers to mean either courtiers or armed retinue. Perhaps it's from this reading that The Hobbit's screenwriters have elevated Bifur to a position as chief 'tank' - though why they chose to 'bifurcate' his forehead with an orc axe and render him almost speechless as a result smacks to me of stretching two jokes a little far. That's not the direction I've gone in, and because I don't have to provide any dialogue, Bifur and Bofur's near-identical characteristics are less of a problem. So then, yellow cloaks as described in the book, plus some patterns around the cloak bottoms referencing in part the colours of the cloak inners.
The major addition to these sculpts is a weapon swap, informed once again by some edited text from an early draft of the novel revealed in a re-read of Rateliff's book this week. Upon their arrival at Bag End (again, personally accompanying Thorin), Bifur and Bofur unwrap a bundle of walking sticks which seemingly turn into clarinets on which they play with the other Dwarves' various instruments. The magical nature of the instruments isn't solely seen with Bifur and Bofur - the other Dwarves seem to bring their instruments out of thin air (or the next best thing), and the instruments probably don't make the trip to the Lonely Mountain with their players (a clue: Balin's instrument is a cello), but the temptation to make some rather special walking sticks the weapons of Bifur and Bofur was great enough for me to give it a go, and so the sculpts' original axes have been cut and shaved away and some quarterstaff walking sticks (made from toothpicks and green stuff) added. I think it works, and I hope the models are better for their addition.