Dear Michael,

It must be fun to shape a character from scratch. When you design wearable cosmetic enhancements to help an actor define a specific role, you get to see your work literally come to life. Be it a knobby nose, a bulbous chin – or, in the case of Naomi Watts' Baltic hooker, a baby bump – your work informs a character's backstory (and, in this instance, her future). When we see a pregnant woman, we instantly understand where her life is headed. Similarly, when we see Bill Murray playing a rumpled, boorish reprobate, we know it's gonna be exactly what we expect. And in St. Vincent, his trademark offbeat charm doesn't disappoint.

Vincent is a misanthropic, alcoholic war vet whose life of quiet decrepitude is disturbed by the arrival of his new next-door neighbours: the recently divorced Maggie and her lonely son Oliver. Maggie begrudgingly relies on Vincent to mind Oliver after school, unaware that the old man's babysitting repertoire includes trips to the racetrack, boxing lessons, and visits from Daka, a pregnant prostitute with the requisite heart of gold. But when Vincent's financial and emotional issues threaten his relationship with Oliver, he must come to terms with his untenable existence.

Depending on the film, your job requires you to create something incredibly convincing or something over-the-top and obvious. Daka's fake tan, fake nails, fake eyelashes, along with Naomi Watts' very fake Eastern European accent, make her realistic baby belly stick out—and not necessarily in the way you intended. Perhaps first-time feature director and writer Theodore Melfi relies too heavily on clichéd cinematic shorthand instead of trusting his characters and their actions to move the story forward. The few relationships Vincent has – with Daka, his bookie, his bartender, and Maggie and Oliver – are all strained. Yet they never seem beyond repair. The tension, therefore, feels manufactured. Luckily, though much of the drama is telegraphed, the cast – particularly newcomer Jaeden Lieberher as Oliver – has enough chemistry to overcome the unexceptional script's shortcomings.

The materials used to create prosthetics haven't changed much in the last few decades, so it's technique that separates a layperson from an artist. St. Vincent doesn't try too hard to stand out in the reluctant father-figure genre (think The Bad News Bears, Bad Santa, and, most notably, About A Boy, from which St. Vincent cribs a lot, right down to the schoolyard bullies and the student assembly climax). Maybe because it knows it doesn't have to. Bill Murray is that rare actor whose very presence is enough to convince the audience that what they're about to see is a cut above the rest. When Vincent cracks his head open trying to chip some ice for a drink, Murray achieved that perfect balance of funny/pathetic.

You created a scab prosthetic for his forehead. It gradually heals over the course of the film, as Vincent, predictably, grows as a person. But with Murray the progression is never boring.