As much as we love to take pictures, there are times our gear may fail, notably memory cards. If you encounter problems, fear not: there are simple solutions out there.
1. KEEP CONTACTS CLEAN.
If you frequently change cards, they will get dirty over time from outside contact. Dirt and foreign objects may cause errors when shooting. Keep cards in containers they came with (or you can buy one). If they do get dirty, a cotton swab with some alcohol can be used to clean the contacts. Let it dry and try usin again. Also, some crds have a lock, read-only switch, check if it's on by mistake.
2. THE MORE, THE MERRIER.
Memory cards, that is. Don't buy cards with big capacities; when they fail, all images in it are affected. It's better to have a multitude of smaller cards so that in case of problems you don't lose all images. The big capacity cards are only recommended if you chose to shoot using the camera's RAW image format or intend to shoot for quite a while.
3. DON'T PANIC
Card acting up? REMOVE IMMEDIATELY, DON'T USE IT. Try using another card, and if it works, your other card may need replacement. And if you still have images in your faulty card...
4. RECOVERY'S A CINCH
Use PhotoRec from http://www.cgsecurity.org/wiki/PhotoRec as it's free and does a good job of recovering your files. It includes documentation to easily recover files from your card. It also includes TestDisk for more intensive data recovery (this, however, requires some advanced knowledge of drive technologies.)
5. AND FINALLY... GET A RELIABLE CARD READER.
There many card readers out there these days, some are cheap and usable, some contain advanced circuitry to speed up transfer as well as wear-levelling system. There are times card errors come from faulty card readers, so do invest in a good card reader. Get a good one that your budget allows.

1. KEEP CONTACTS CLEAN.
If you frequently change cards, they will get dirty over time from outside contact. Dirt and foreign objects may cause errors when shooting. Keep cards in containers they came with (or you can buy one). If they do get dirty, a cotton swab with some alcohol can be used to clean the contacts. Let it dry and try usin again. Also, some crds have a lock, read-only switch, check if it's on by mistake.
2. THE MORE, THE MERRIER.
Memory cards, that is. Don't buy cards with big capacities; when they fail, all images in it are affected. It's better to have a multitude of smaller cards so that in case of problems you don't lose all images. The big capacity cards are only recommended if you chose to shoot using the camera's RAW image format or intend to shoot for quite a while.
3. DON'T PANIC
Card acting up? REMOVE IMMEDIATELY, DON'T USE IT. Try using another card, and if it works, your other card may need replacement. And if you still have images in your faulty card...
4. RECOVERY'S A CINCH
Use PhotoRec from http://www.cgsecurity.org/wiki/PhotoRec as it's free and does a good job of recovering your files. It includes documentation to easily recover files from your card. It also includes TestDisk for more intensive data recovery (this, however, requires some advanced knowledge of drive technologies.)
5. AND FINALLY... GET A RELIABLE CARD READER.
There many card readers out there these days, some are cheap and usable, some contain advanced circuitry to speed up transfer as well as wear-levelling system. There are times card errors come from faulty card readers, so do invest in a good card reader. Get a good one that your budget allows.