The only time a poodle absolutely has to get a haircut is for the show ring. Otherwise, let his coat grow long, cut it short or put him in dreadlocks. He still needs to be brushed at least every other day, and an ungroomed poodle is an unhappy poodle.
Brusha, Brusha, Brusha
Brushing a poodle is a long and tedious process for dog and groomer that must be done before any clipping or cutting. Poodles shed very little, and because their coat is curly, the loose hairs stay in the coat. You have to remove these, along with any mats and tangles, from the coat with a slicker brush, and it's a bit like carding wool. You brush a while, starting at the tail, and then you take a break; so does the dog, unless he's one who goes to sleep while being brushed. Then back to brushing. Once the whole coat is brushed out, the dog can be bathed and dried and the fluffy coat can be sheared, scissored and packed into any number of fancy shapes and styles, or shaved off altogether.
The adult show poodle is limited to only two haircuts -- the Continental, with its lion-like mane, tasseled bare tail and pom-poms on hips, knees and ankles, and the very similar English Saddle clip, with more hair on the hind legs. These tufts were, in the distant past, supposed to warm the joints of the duck-retrieving poodle in cold water. They remain as the official and distinctive topiary of the breed.
A poodle under a year of age can go into the show ring in a puppy clip, which is uniformly fluffy but shaped all over the body and legs with close-shaven face, feet and tail (except for the tassel). A bit shorter and you have the lamb clip, the kennel clip or the utility clip.
In between the massive mane and stylized patches of the show clips and the plain Jane of the utility clip are many different haircuts that are the result of an owner's fantasy or a groomer's inspiration. The most unusual hairdo for a poodle isn't a haircut at all -- it's from Jamaica, mon. The coat is separated (after brushing, of course) into small sections and in each of these the hair is encouraged to curl into long, tight curls like a Rastafarian's dreadlocks. This is the rarest of poodle hair styles because it is so difficult and time-consuming to maintain. The cords have to be separated by hand daily so they don't turn into one giant mat. A corded coat is a nightmare to keep clean, requires special shampoo for bathing and takes a long, looong time to dry. Do yourself and your dog a favor and give this one a miss.