There are several factors to getting a sharp image, the lens is only one of them.

Lighting

If you have a well-lit shot it will be much easier to get the crispness you want because you can get higher contrast lines.

Shutter speed

This is actually pretty closely related to a well lit shot, but you want to make sure your shutter speed is fast enough to avoid camera shake, which will cause blurring. A good place to start is with a reciprocal of the lens length (i.e. for a 50mm lens, at least 1/50s).

Camera shake

If you can't get lighting good enough to use a fast shutter speed, then you just have to do your best to avoid camera shake. This means working on you technique, both with holding your camera, and with pressing the shutter, or if your lens has image stabilization (or vibration reduction) then use it. When none of the hand held methods work, then use a tripod.

Aperture

Every lens will have a aperture at which it is the sharpest, a good place to start is in the middle of the range, typically around f/8. This is a bit complicated, because there are 2 opposing elements at play, depth of field, and diffraction. Ken Rockwell has an in depth article about this if you really want to study it.

Lens Quality

Some lenses are just better quality and will have less aberrations, so a shot taken with a kit lens will probably never be as sharp as a correctly-exposed image from a Leica 50mm f/1.4. That is not to say that any shot taken with a superb lens will be better than any shot from a kit lens, because that is certainly false. It does mean that the upper range is higher of some lenses.