For close-ups and situations in which a camera's autofocus doesn't quite cut it, switching to manual focusing can help you get the shot. Low-end cameras often omit manual focusing or allow only stepped focusing, which forces you to choose from a few preset distances. It's also a good idea to test out a camera's autofocus before you buy; some cameras struggle to lock in on a focus point at full telephoto or in macro mode, meaning you may not be able to capture your perfect shot.

If you have an existing storage card that you'd like to use with your new camera, make sure that it's compatible with your new purchase. Most cameras on the market today use SD (Secure Digital) or SDHC (Secure Digital High Capacity) format cards. are more expensive, offering storage capacities up to 32GB, but they're not backward-compatible with standard SD slots. There's also a new format on the block: SDXC, which supports storage capacities up to a whopping 2TB; those are even more expensive, and they aren't compatible with all SD/SDHC card slots.

In addition to storage capacity, there's also the speed issue to consider. SD and SDHC cards have a "Decoding Class" rating listed, which refers to the data-writing rate for each card. The higher the Class number, the faster the write speed; if you're planning on shooting video or using a high-speed burst mode, look for a Class 4 or Class 6 card at the very least.

To complicate matters further, there are a couple of other formats out there. Some cameras support MicroSD or MicroSDHC cards, a smaller version of the SD card format that isn't compatible with full-size SD slots. Older Sony cameras take MemoryStick cards, and older Olympus cameras use the XD card format; both companies' new cameras now support SD/SDHC cards. What's more, many higher-end DSLRs have a larger-format CompactFlash card slot.