Strictly speaking, you can pull from any remote branch directly:

    git fetch remotename
    git merge remotename/master

But you usually just want to rebase your changes onto the latest HEAD:

    git fetch remotename
    git rebase remotename/master 

Merging will place the remote branch's changes after yours, which will make your history a nightmare, especially if you're going to continue working on your branch. Rebasing will place your local branch changes after the latest changes to the main branch.