I've been playing for a couple days now and I've found that the consumables are almost useless.

The only time I've needed the crossbow is to bring down the griffin.
Other times I've used it, but not really needed it, is when fighting a group of bandits and exploiting the fact that they are tethered to their camp and me just backing up to plink them to death with it. :-s

Potions... now those are supposed to be powerful and lasted long enough to be effective; in the previous two games they are.
In this one, they are nearly useless because they last so short a time or heal very little!
Most potions in the prior game lasted between 3 and 5 minutes; this made sense and was actually long enough to finish even boss battles.

Now I have this plus damage potion and it lasts an insanely short 20 seconds!
This is useless, because most group and boss battles last far longer then that.
Those are the only two battles in which I'd actually need a potion and they run out before they can even be useful!

Bombs are only useful for destroying lairs.
I've never used bombs much, because my potions and sword skills in previous games allowed me to carry through, with only a little additional sign usage.
However, when I actually needed them in TW3, I find that they do minimal damage and the stun bomb only dazes them for three full seconds.
Since I have no leap attack, that's also useless for anything other then running away... and I don't need it to run away... there's a sprint button!