I'm using git on a new project that has two parallel -- but currently experimental -- development branches:
git merge --no-commit
You use the cherry-pick command to get individual commits from one branch.
If the change(s) you want are not in individual commits, then use the method shown here to split the commit into individual commits. Roughly speaking, you use
git rebase -i to get the original commit to edit, then
git reset HEAD^ to selectively revert changes, then
git commit to commit that bit as a new commit in the history.
There is another nice method here in Red Hat Magazine, where they use
git add --patch or possibly
git add --interactive which allows you to add just parts of a hunk, if you want to split different changes to an individual file (search in that page for "split").
Having split the changes, you can now cherry-pick just the ones you want.