So I am always looking for the way to change all files or directories in a directory to a certain set of permissions. Here are the following shell commands that you can use to accomplish it.
# For Directories
find ./ -type d -exec chmod 755 {} +
# For Files
find ./ -type f -exec chmod 644 {} +
To change the ownership of files recursively you can use the following command
chown -R username:groupname ./*