Think of your Litecoin Wallet as a Bank. If the doors on the bank are left wide open then anyone can steal your coins.
To secure your Litecoin Wallet completely you simply need to carry out the following
1) First of all make sure that your Wallet is encrypted. You can do this by clicking on Settings – Encrypt Wallet and entering a password twice. Make sure you dont forget this password. If you do then you will LOSE all your coins. At this stage most people are happy to continue using their Litecoin Wallet however if you want to be 100% sure that your coins will never be stolen or lost then you should proceed with steps 2 to 6.
2) Open your Litecoin Wallet and note down all of your Litecoin Addresses found under the Receive tab. You can right click and select copy then add to
3) Close your Litecoin Wallet
4) Navigate to your Litecoin Folder. (In Linux this would be ~/.litecoin , In Windows the file is found %APPDATA%\Litecoin\)
5) Copy the wallet.dat file from this folder on to 5 separate USB Sticks. Then delete wallet.dat from this folder
6) Keep your USB Sticks in a secure safe
You may then ask me how will you know what your LTC Balance is? Well you can still check your balance by simply heading over to http://block-explorer.com/
Enter your Litecoin Address and this will give you your current balance according to the blockchain (essentially a transaction ledger). If you have multiple Litecoin Addresses then repeat this exercise for each address and then add up the numbers. In most cases you will be using one address more than others.
If you ever need to send LTC in the future then you simply insert one of your USB sticks in your computer and copy the wallet.dat file back to its original location.
Then run the Litecoin Wallet and use the -rescan flag as follows. (Example is shown in Linux below)
This will rescan the block chain for any missing wallet transactions
By removing the wallet.dat files from your computer it means hackers cannot reach your coins. It also means if someone stole your computer/laptop the coins are still secure.
Ideally you should keep some USB backups in one location but also keep some offsite at another location.