To add files to your castle you just do
homesick track <FILE> <CASTLE>
This will move the file to your castle and create a symlink.
You also don't have to create a separate repo of your castle outside of your ~/.homesick
directory. To initiate a new castle, you just do
# create castle homesick generate ~/.homesick/repos/<CASTLE> # enter castle directory homesick cd <CASTLE> # add a git remote git remote add <REMOTE>
See also the homesick readme and
homesick help