There are a few ways you can prolong the life of your memory cards and preventing data corruption or accidental data loss. These tips aren't the be all and end all but will reduce the potential of a catastrophe.
1. Formatting your cards in the camera – not in the computer is a great tip. This helps to ensure that no unwanted or unneeded files make their way onto the card from the computer. But I also do a deep format of my cards about every 6 months in my computer, this will help isolate any bad sectors (problem areas of your cards) and flag them.
2. Safely Remove your cards. If your using Windows then use the "Remove hardware" function or Command + E on a Mac. If your operating system is accessing the card when you remove it unsafely then this can actually "damage" file system. It also pays to wait a few extra seconds before you remove your card, just to make sure that everything is safe.
3. Back-up your cards before you format and delete any images. The best practice is to have at least 2 backups when your travelling, just in case anything happens to your back up. When shooting a wedding I personally back up my cards twice, once to a notebook and once to an external hard drive. I also don't format my cards until I'm home safe. This way I actually have 3 copies of all the data, it may be a bit more expensive to do things this way but I don't want to run any risks.
4. Number or name your card, to avoid any confusion when you are using multiple cards. So you can identify your cards easier when your in a studio/workshop/photo walk etc. As all my cards are from 1 manufacturer I can also tell which of my cards is oldest or the most used.
5. Buy a Brand name card. There are actually only a few major manufacturers of the components used in memory cards. They actually manufacturer different quality standards depending on who they are building for and how much the customer is paying. There for when they make components for generic cards, the quality control as is usually not up to the same standards as the big names.
6: Be aware of counterfeit cards. If the price seems to good to be true then it probably is. Over the last few years there have been a lot of cheap on line deals that a lot of photographers have fallen for. The scams vary from fake brand names to smaller cards than describe. Some of the better counterfeit cards sell only slightly cheaper then the originals, that way they arouse less suspicion. In many cases the packaging may look perfect but the quality of the print on the card itself, or any literature in the packaging my indicate fake cards.
7. Manufacturers recommendation. I have seen a lot of cameras that come with a recommendation to only use cards from a specific manufacturer. Personally I think this is simply some sort of business arrangement between the 2 companies (on in some cases there own subsidiaries). As long as your card is from a trusted manufacturer you should be fine.
8. Transport your cards properly. Just rattling around in your camera bad isn't a safe way to store or transport your memory cards, get a small wallet or hard case designed for the types of cards that you use.
9. Copy you files to the computer before editing. Don’t edit files on the card when its in your card reader. The memory card is designed to get data from the camera to the computer and not to be used as a hard drive.
10. Don’t delete images in camera. Cards are very cheap so get enough to do the job. An image can't truly be judged by the small screen on the back of your camera. You may actually be getting rid of a fantastic photo with out realising it, or change your mind about it later.
11. Your can un-delete. If you do delete an image accidentally stop using that card, and obtain a data recovery program to try to restore the images. Several of the major manufacturers ship their cards with recovery software. When you delete any data it isn't actually gone, the segment is simply marked that it can be rewritten to. So when you keep shooting after the deletion you may mess up the chance to recover the lost images.
12. Your card may affect your battery. Some very old "cards" like the IBM Micro-drive were actually very small hard drives and they required a lot more power than the same same sized card. The new high speed cards may also require more power from your battery.
13. Format shared cards. If you share cards with friends, (put them into other people’s cameras or computers) always use a fresh formatted card. And reformat it before you use it. This can cause a crash since the other camera or computer may attempt to write a system, desktop or file of unknown format to the card. You can also end up changing the numbering system on your camera, if you and your friend use the same brand of camera.
14. The latest isn't always the greatest. Just because someone brought a 128 GB card out onto the market doesn't mean run down to the shop any buy one. We are pushing the boundaries of technology every day so to let the marketplace test these cutting edge technologies to make sure they are reliable. and 2x 64gb cards will probably be cheaper then 1 128gb card anyway
15. Turn your camera off before removing or inserting your memory card. The camera manuals always say to only insert your memory card when your camera is turned off to eliminate “voltage shock”or "write errors". I admit I have changed cards on the fly more than once with out any problems in the past, but as all my cameras now have 2 memory card slots i can avoid this unnecessary risk.
16. Avoid Filling Your Cards Completely. I have a friend who recently had an issue with a memory card. When he took it into the store he bought it from for advice they asked if he’d completely filled the card with images. When he said he had they told him that this could occasionally cause problems with some types of cards. I’d not heard this before and am a little skeptical about it myself – but it’s probably worth keeping in mind. I guess the advice is to regularly take images off your cards rather than doing it just when they are full. This is common sense anyway as it stops the heartbreak of losing gigabytes of images if you lose a card/camera or have a card error with a three quarters full memory card.
17. Keep Your Camera Up to Date. Camera manufacturers will release firmware updates from time to time. These keep your camera up to date with any fixes for errors or problems that are identified with a camera. Some of these can relate to the camera’s interaction with the memory card.
18. Periodically Update Your Cards. While memory card life spans have increased significantly over the last few years – they do have a limited life and will need to be updated from time to time. With prices coming down this is fortunately a less and less expensive task
19. Don’t Switch Off Your Camera too Quickly after Shooting. This tip is for those of us who shoot in ‘burst’ or ‘continuous shooting’ mode. When shooting lots of images quickly a camera needs a little time to write all of the data you’ve taken to the memory card. If you’ve taken numerous images very quickly your camera will be ‘buffering’ images and if you switch it off during this process you’ll lose images and could even find yourself with a system error (note: some more modern cameras have fixed this problem and will now continue buffering after you switch them off).
20. Common Sense Maintenance. It should go without saying – but keep your cards dry and clean, don’t expose them to extreme temperatures, don’t drop, bend or puncture them and don’t expose them to h3 electro/magnetic currents. Storing cards that are not in use in a plastic casing (usually supplied with the card) can give it an extra layer of protection.
21. Right cards for your environment. Going on a camel safari over the Sahara or photographing penguins in Antarctica may sound amazing , but not every card will withstand extreme environments and temperatures . If you check the manufacturers instructions and recommendation that came with your card it should list the minimum and maximum operating temperature of your card.
22. Know your card's life expectancy. Memory cards are one of our most wonderful modern inventions, because they store a massive amount of information with no moving parts. That means you can drop them, sit on them, even accidentally run them through the washing machine and most of the time they'll keep on ticking (please don't try that just to see if it works ). Nonetheless, they're not indestructible, and they have a limited lifespan. Memory cards can be written to a set number of times only, so your cards will eventually stop working. Since you can't easily track the number of times you're written data to your memory cards, a more practical alternative is to expect your card to work for about 8-10 years. But lets face it if you keep you card for 8 years it will probably be smaller that the size of the files your camera can take so. A few years ago I was shooting with 2gb cards today I use 16 and 32 gb cards. So don't wait until they day that your card is unusable to replace it.