Because grass plants are vigorous and fast growing, regular mowings are essential.  Mow whenever the grass demands it--a good rule of thumb is never to cut off more grass than you leave.  If the recommended height of cut is two inches, mow when the grass is three and one-half inches high.  If height of cut is one inch, mow when the grass is just under two inches.

The different species of grass require different mowing heights.  In shady spots, cut grass less frequently and at a height a half-inch taller than normal.  This will help conceal thin growth that's unavoidable where sunlight is sparse.

You have many choices when it comes to mowing equipment.  There are advantages and disadvantages to both reel and rotary machines.  Generally, though, reel mowers make a cleaner cut and are especially good for low-cut lawns (for example, bent grass turf).  Rotary mowers are more maneuverable, more easily lifted and stored.  When dull, rotaries tend to fray grass tips rather than cut them, resulting in a brownish tinge when the damaged grass leaves dry out.

Perhaps the most important mower considerations are the size, shape, and quality of your lawn.  Choose a mower large enough to handle the job, and then keep the blades sharp and in good repair.