We sign a check, address a letter or leave a note and never think twice about the complexity of what we have just done. Yet for some children, handwriting is a skill that may take years to master.

Occupational therapists working with these children describe handwriting as one of the most challenging and complex skills to develop and the one for which most referrals for their services are made.

Occupational therapist Paige Tyson, who works with general and special education K-3 students at PS 264 in Bay Ridge on a variety of occupational issues, talks intently about the work she does to develop the fine motor skills needed to correctly grasp a pen or pencil; the dexterity needed to properly use the thumb, index finger and pinky; the intricate and fluid interplay of finger muscles; and the stability of the wrist.

She adds visual motor skills into the equation — making sure each of the six muscles in each eye is doing what it is supposed to do so children can form letters, space them, stay on the line and properly copy what they see.

That’s a tall order for many children. As David Clarke, who has more than 32 years of experience as an occupational therapist and works with autistic children at PS 37 on Staten Island, pointed out, challenges with handwriting can overlap with other disabilities, so it’s a “challenging and fascinating population.”

Most occupational therapists, many of them with master’s and doctoral degrees, are scheduled for 40 sessions a week, and what’s described here is just a glimpse of what their jobs actually entail. They meet with K-12 students for 30 minutes — one-on-one or in small groups — once or twice a week depending on the services mandated.

Because of the repetitive nature of the work, therapists must have a strong sense of mission and lots of patience. To keep children from getting bored, they rely on a big bag of creative tricks.

Tyson divides 30 minutes into minisessions. She may have students jump rope to build gross motor skills, string beads to improve fine motor abilities and complete mazes to sharpen their visual and perceptual skills. To improve sensory skills, students may get a big bear hug. Tyson ends the session with a functional task like writing a letter.

Working with a 1st-grader making the letter H, Tyson repeats over and over again, “straight down, straight down, now make a bridge.” After the session, she explains to an observer, “It’s not only what you say but that you repeat it and always in the same way.”

Because handwriting does not improve overnight, occupational therapists are alert to children’s feelings of being losers or giving up. As occupational therapist Esther Sung of PS 8 in the Bronx pointed out, “Our children have to feel success. We don’t want tears, and we don’t want them to be scared of writing.”

Tyson sets “teeny, tiny goals” so the child sees success at each session and hears only words of encouragement. “That was wonderful, Domenick,” she tells one 1st-grader. “Good job, Eldin,” she tells a kindergartner.

Occupational therapists work closely with physical therapists in what Clarke terms a “side-by-side” relationship and with speech therapists, classroom teachers and parents, all of them watching for and cheering each sign of progress.

“I love this time of year because the child who couldn’t form letters in September now can,” said Tyson.

Summing things up, she said, “I love what I do. I would never stay working for peanuts if I didn’t love what I do.”