This school year, you’re re-evaluating your disposable income — meaning you won’t spend a penny on throwaway plastic lunch baggies.Settle into a waste-free routine with Citizenpip’s lunch gear, a collection of reusable, toxin-free food containers and accessories designed in Burlingame. On-the-go kidlets will find sturdy new companions in the the stainless steel water bottles, utensil sets, and jars that keep meals hot or cold.Airtight, lightweight food cases come in three sizes and are machine washable. Designed for tiny hands, flip-down lids are leakproof and close with an unmistakable, satisfying click.Prices range from $3 to $69 — worth every cent.Available at Rockridge Kids, 5511 College Avenue, between Ocean View Drive and Lawton Avenue, Oakland (510-601-5437); online at citizenpip.com. TREKA Midsummer Urbia AdventureWhat: The free, drop-in nature exploration for ages 12 and under is set amid the trees of Sigmund Stern Grove.Why: Get down to earth.When: Wed., 10 a.m.-1 p.m.Where: 19th Ave., at Sloat Blvd. (415-252-6252). Adventure packets available at the Urbia table in the tent area east of the stage. R.S.V.P. to email@example.com.CREATEFolksy Family Day What: Make a painting on wood, with Clare Rojas’s wall quilts (currently on exhibit) as your inspiration.Why: You’ll feel as if you’re inside a picture book.When: Sat., 1-3 p.m.Where: Museum of Craft and Folk Art, 51 Yerba Buena Ln., at Mission St. (415-227-4888). Materials provided with a $5 donation.GOGreen Gulch Farm Children’s Program What: A fifteen-minute dharma talk for wee Buddhas is followed by crafts, yoga, and gardening.Why: Experience the famously Zen slice of the Marin coast.When: Sun., 10-11:30 a.m.Where: 1601 Shoreline Hwy., at Muir Beach (415-383-3134). Check in near the southwest side entrance of the zendo. Suggested donation, $10 per family.Photo: Courtesy of CitizenpipUp to 70% off Soixante NeufDesigner Joie Jager loves making her feminine, worldly jewelry as much as you’ll love wearing it. Scoop up her gems while they’re up to 70% off on Swirl.