This is not applicable for a wide range of two-headed creatures because I can't imagine this as an ultimate survivor strategy but there was mention of tool use in finches in another answer, so technically, having two heads with a long neck and a type of mouth or beak that can grip well could be a substitute of having two arms with opposable thumbs. (In a creature that is unable to use its limbs in a similar way because they were just not designed for it or are in the long place/height.) I.e. make the species capable of advanced tool use.

For this to become a trait, a lot of favourable conditions need to be in place to 1) introduce this as a trait and not just a one-time coincidence of birth and 2) a safe environment for the new species in that awkward phase when they haven't yet worked out how to use the new trait well enough to compensate for its drawbacks and turn it into a net benefit.

This is not applicable for a wide range of two-headed creatures because I can't imagine this as an ultimate survivor strategy but there was mention of tool use in finches in another answer, so technically, having two heads with a long neck and a type of mouth or beak that can grip well could be a substitute of having two arms with opposable thumbs. (In a creature that is unable to use its limbs in a similar way because they were just not designed for it or are in the long place/height.) I.e. make the species capable of advanced tool use.

For this to become a trait, a lot of favourable conditions need to be in place 1) to introduce this as a trait and not just a one-time coincidence of birth and 2) a safe environment for the new species in that awkward phase when they haven't yet worked out how to use the new trait well enough to compensate for its drawbacks and turn it into a net benefit.