Always make sure your batteries are charged sufficiently before taking pictures and ESPECIALLY before downloading photos to the computer. If the battery dies during transfer, the card can be damaged and photos lost. It's a good idea to purchase extra battery/batteries in case you need them. Or use a card reader.
Always reformat the card in your camera each time after downloading and saving the pictures on your computer. Don't use the computer to format the card.
Wait a few moments until the camera is through writing to the memory card before turning off the camera.
Do not remove the card from the camera while the camera is turned on.
Do not touch the metal contacts on your memory card.
Avoid static electricity charges and be extra careful when handling cards in low humidity areas.
Keep cards away from strong magnetic sources, and extreme heat and cold. Walk-thru airport x-rays and scanners are safe, but be careful of the stronger x-ray equipment used to examine checked baggage.
Don't remove the card from a card reader too quickly. Wait until it has finished communicating with the hard drive and all files on that card are closed.
If a memory card problem occurs, stop using the card immediately. Do not reformat the card or delete pictures. Use an Image Recovery program or send the card to an Image Recovery Lab to retrieve the files.
Be careful with the Delete All and Format options in the camera. Don’t let people unfamiliar with the camera navigate the menus as they might accidentally delete the photos.
IMAGE RECOVERY SOFTWARE for recovering images from damaged cards: