Image sharpness is vital for exciting eye catching pictures. Though there may be artistic reasons for an intentionally out of focus image - for not lets assume a oft one won't impress anyone . And ensuring your images are sharp is easy once you know how.
Image sharpness is controlled by four things, accurate focusing by setting up your auto focus, depth of field, avoiding camera shake and keeping the lens clean because bits of dirt and finger smudges affect image sharpness more than you might think..
Once you know how to set the first three up appropriately for the shot you're taking, in camera image sharpness pretty much takes care of itself.
When you're out taking photos always zoom in after taking a shot to make sure it's sharp. It's very disappointing when you get home only to find the image you were so excited about when you took it is actually soft.
You'll need to watch all the tutorials in this section because image sharpness isn't controlled by just one thing - it's a combination of several.
7 Steps to Perfect Pictures has massively improved my retouching skills overall.
Previously I'd used Lightroom to catalogue (I'm much better organised now I'm following Mike's example) and then fiddle with images in an unstructured way. Now I know what I want to do and how to do it.