Many have stored their wallet seed phrase in the best way and safely. The way I put my wallet seed phrase is safe for me but may not be safe for many people. I wrote down the seed phrase of my wallet in the notebook. I have it set to my Google Drive for extra security.  I know that even if my notebook somehow gets corrupted, the wallet seed phrase stored in my Google Drive won't. Because as long as I have Gmail I think I can safely recover my wallet passphrase. This method seems to be the best method to me.