1. Before beginning handwriting the child should have a good understanding of how writing instruments work.  To accomplish this the child should have free time to explore with pencils, pens, crayons, markers etc.
2. The act of holding and writing with a pencil is quite a feat for a small child.  Often their small muscles are not developed enough to begin this difficult task.  In order to help strengthen those muscles encourage your child to squeeze and manipulate play-dough, use scissors, play with lacing beads or cards, use clothespins etc. 
3. Much of the time children will have a good grasp on the alphabet long before they are ready for formal handwriting instruction.  To help transition the child into writing you may want to give him a pan of sand, shaving cream or pudding to practice letters in.  This is the epitome of combinding fun and learning for most kids.
4. Try other early writing activities such as sidewalk chalk, writing with water on a hot sidewalk, playing with refrigerator magnets, making an alphabet book from magazine pictures and making fun letter shapes with fingerpaint.
5. Kinesthetic (active) learners may benefit from making their own bodies into letter shapes, baking cookies or pretzels into letters and running their fingers over sandpaper shaped letters. 

Tips and Tricks for Beginning Writers

1. Don't expect too much.  A child just beginning to write should only be asked to write or copy a word or two at a time.  Build up to longer sentences over time.  Be sure to take your cues from the child; if he is not enjoying writing back off a bit and give him more time in the pre-writing stage.
2. Pencil grip is an important factor in sucessful writing.  In order to get the grip just right ask the child to hold out his hand with palm facing out.  You will then gently put the point of the pencil on his palm.  He is to grab the pencil with ALL fingers in just that position.  Once the child has hold of the pencil from the pointed end then you should flip it up into correct position.  Once you show the child how to get the grip this way he should be able to do it correctly himself everytime.
3. If the child is having trouble controlling a large pencil try the small ones used at baseball games for keeping score.
4. Get your child excited about writing by teaching him to write his name FIRST.