1. You can export private key (dumpprivkey in console) and print them on paper and then even if you lost/delete wallet.dat you can easy retrieve wallet.dat file on any PC/Mac

2. Split your wallet and money on 10 wallets and store it on external HDD/USB stick

3. I only copy ONE wallet.dat file when I need SEND money and after that delete it from my system

4. Install Linux as second system or run it from USB key to increase security