Just as you mastered the art of packing the perfect diaper bag, he’s potty trained and headed to preschool. Help him make sure he’s got this one in the bag.Step One: Find the perfect carryall. It should be big enough to hold essentials (a snack, a sippy), but not so large that it weighs him down. Our pick: the handmade cotton and linen messenger bags from Mee a Bee ($25-$40), sized to sling across the chests of scholars ages 3 to 6.Step Two: Leave a paper trail. Ecojot’s latest collection of spiral-bound sketch pads and journals ($4.50-$17) supports the Jane Goodall Institute with collage-inspired cover images of endangered species. But it’s the recycled, unlined paper and heavy-duty back cover that give kids what they need to write and draw.Step Three: Color it in. P’kolino’s art set ($20) is a cornucopia of jumbo markers, triangle and wrapper-free crayons, and hexagonal colored pencils — all designed to fit little hands. So practicing good form is as easy as one, two, three.Looking for the perfect lunch box? Check out our photo gallery.PLAYSouth Lake Union Block PartyWhat: A farmers market, food samples, and a kids’ area with crafts, a bounce house, and more. Why: Outdoor screenings of Thriller and Zombieland give a delightful case of goose bumps. When: Fri., noon-11 p.m.Where: South Lake Union Discovery Center, 101 Westlake Ave. N. (206-342-5900). Admission is free.SPLASHRodney the SharkWhat: A timid fish learns to be courageous in a show by Rowbes Puppet Productions (ages 3 and up). Why: Replenish your supply of bedtime books afterward. When: Thurs., 10:30-11:30 a.m.Where: The Seattle Public Library, Central Library, 1000 Fourth Ave., Microsoft Auditorium (206-386-4636). Admission is free.CHOW12th Avenue Neighborhood FestivalWhat: Nibble snacks from area restos ($5 and under), stop by shops, and visit the face painter. Why: The city’s lively buskers line the streets. When: Sun., noon-6 p.m.Where: 12th Ave., b/t Madison & Pike Sts. Admission is free. Photos: Courtesy of Jacqui Miyabayashi / Mee a Bee; Courtesy of Ecojot; Courtesy of P’kolinoUp to 75% off MLHLynne Hiriak (of Cardigan fame) ups the knitwear ante with ’70s- and ’80s-inspired dresses and sweater tops with color blocks, sequins, and vintage-meets-modern shapes. Take up to 75% off on Swirl.