Illustration: Cecelia Granata

Apologize!
Before Rosh Hashanah (Monday 29–Wednesday 1), it’s traditional to ask forgiveness from both friends and enemies for all of your wrongdoings. A mass e-mail may sound like the perfect exit strategy, but Rabbi Eliyahu Stern, host of the Rabbis Roundtable on The Jewish Channel, says the apology must be personally communicated. “The whole point is not to ask the apology, but to put the awkward effort into seeking it,” he tells us. “Then it’s an earned forgiveness.” Easier said than done, buddy. If you’re gonna take the coward’s way out, post on the National Jewish Outreach Program’s Project Forgiveness blog (projectforgiveness.blogspot.com)—it’s one part PostSecret, two parts Jewish guilt.

Attend!
Seats for the High Holiday services are expensive—yes, synagogues charge—but there are houses of worship that offer free services too. Kehilat Orach Eliezer (891 Amsterdam Ave between 103rd and 104th Sts, koe.org), an “almost Orthodox” congregation, is exceptionally welcoming, and Kol HaNeshamah, another upstart, hosts its services at the Stephen Gaynor School (148 W 90th St between Amsterdam and Columbus Aves; 646-678-2084, kolhaneshamahnyc.org). R.S.V.P. required.

Atone!
On the first afternoon of Rosh Hashanah, the Jewish people walk to the nearest body of water (a river, pond or lake) and partake in the tashlikh by symbolically throwing away their sins, often in the form of small pebbles or bits of bread. This signals your one and likely only chance to combine Olafur Eliasson’s majestic waterfalls () with ancient Jewish tradition.

Anoint!
On the second night of Rosh Hashanah, it’s customary to bless a fruit you’ve not eaten the year before. The Orchard (1367 Coney Island Ave between Avenue J and Cary Ct, Coney Island, Brooklyn; 1-800-222-0240, orchardfruit.com) stocks both pomegranate and Israeli-grown sabra. And FYI, all fresh fruit is kosher, so long as you don’t wrap it in bacon.

Hark the shofar!
The sounding of the shofar, or ram’s-horn trumpet, is an integral part of High Holiday services. Some Chabad Centers host DIY shofar-blowing workshops, but if you can get your hands on the horn of a ram, antelope, gazelle or goat, My Jewish Learning (http://myjewishlearning.com) has posted a step-by-step guide.

Watch what you eat!
Eating the day before the Yom Kippur fast (October 8–9) is just as important as not eating on the actual day. Jodi Buckman, a nutritionist at Mount Sinai’s Ruttenberg Treatment Center, suggests a balanced meal of complex carbohydrates, protein and fats. “Hydration is also important,” she warns. “Drinking extra fluids such as Gatorade will help.” For the prefast feast, try kreplach from Mr. Broadway Kosher Restaurant (1372 Broadway at 38th St; 212-921-2152) and fresh challah from Moishe’s Kosher Bake Shop (115 Second Ave at E 7th St,212-505-8555).

No leather shoes!
You’ll never find a more perfect excuse than Yom Kippur to wear checkered Vans with a suit. Blades Downtown (659 Broadway between Bleecker and E 3rd Sts, 212-477-7350) sells a slew of nonleather slip-ons, and ladies can check out Natalie Portman’s newly launched vegan shoe line at Té Casan (382 West Broadway between Broome and Spring Sts, 212-584-8000).

No primping!
Lock away your toothbrush, deodorant and lipstick—and don’t even think about showering. Yom Kippur is a day in which Jews achieve a level of holiness akin to angels. “It’s about getting back to basics,” says Rabbi Stern. “[We must] detach ourselves from the physical in order to achieve the spiritual.” Swing by your local Duane Reade the night before and pick up SmartMouth’s 24-Hour Fresh Breath Long-Lasting Mouthwash. Your shul buddies will thank you.

No sex! (No kidding.)
Put down the bong, schlemiel. Despite their name, the High Holidays forbid all forms of physical euphoria—including sex. But considering the hygiene restrictions, who’d want to shag on Yom Kippur anyway?

NEW TO THE JEW? The East Side Synagogue is offering High Holiday services for the unaffiliated and uninitiated. The liturgy is presented in English and Hebrew, but the overall vibe is very 101 (with music!). For more info, call 212-209-6801 or visit besthighholydayservices.com.