Thus it is wise to keep the number of your inodes(files/folders) as small as possible.
To reduce the number of inodes your account uses, you should remove all files/folders which don't need.
Check the number of cache files you have; applications such as Joomla can generate a lot of cache files; you should regularly check your cache folder and reduce the number of cached files you keep;
if you have Default Address (catch-all) enabled, make sure you check the mailbox regularly and delete all mails you don't need;
Check your cPanel's main email account regularly; the mails for it are kept in:
where username is your cPanel username. You can manually delete the messages in these folders using cPanel's File Manager or any favorite FTP client;
You should also check your email accounts regularly and delete any spam messages from them;if you have email accounts you don't need or use, it would be best to remove them;