Short answer

• For consistently the best overall fashion discounts in Singapore: ZALORA (fashion‑focused platform with frequent sitewide promos, bank codes and flash sales). (ZALORA.sg)
• For the deepest one‑off bargains during mega sale events (and lots of store/brand variety): Lazada and Shopee (huge marketplace discounts, flash deals and brand boxes during 10.10 / 11.11 etc.). (apps.apple.com)
• For very low prices on fast‑fashion trends (huge coupon/voucher stacks during big sales): SHEIN. (sg.everydayonsales.com)
• For promotions on regional / direct‑to‑consumer fashion brands (Pomelo, Love, Bonito): check the brand apps/sites — they frequently run app‑exclusive and first‑time buyer discounts. (Picodi.com)
• For coupon stacking and small‑ticket steals (time‑sales, vouchers): Qoo10 is useful. (sgdtips.com)

Why these recommendations

• ZALORA is built just for fashion/beauty so it runs regular sitewide %‑off codes, bank/partner promos, VIP flash sales and brand clearance events — making it the most reliable place to find targeted fashion discounts. (ZALORA.sg)
• Lazada and Shopee are general marketplaces but their mega sale days (10.10, 11.11, 12.12 etc.) deliver extremely deep markdowns across many fashion brands plus app‑only brand boxes and time‑limited flash deals. If you hunt on those sale days you’ll often get the steepest absolute discounts. (apps.apple.com)
• SHEIN often advertises very large % discounts and extra vouchers around big events, so it tends to beat other retailers on baseline low prices for trendy pieces during its sale windows. (sg.everydayonsales.com)
• Pomelo, Love, Bonito and other regional brands run frequent app‑only promos, first‑time buyer codes and up to‑70% sale sections — good for mid‑range fashion that still goes on big sales. (Picodi.com)
• Qoo10’s time sales, cart vouchers and bank‑partner coupon packs let you stack discounts on low‑priced items — handy for bargains and everyday basics. (sgdtips.com)

Practical tips to get the best discounts

• Wait for mega sale days (10.10, 11.11, 12.12) for the deepest cuts — marketplaces and fast‑fashion sites run their biggest promotions then. (straitstimes.com)
• Use app‑only codes and first‑time buyer vouchers (many retailers reserve better codes for their apps). (singsaver.com.sg)
• Combine retailer promos with bank/card partner codes or wallet promotions (ZALORA and others often have bank‑specific 10–15% offers). (ZALORA.sg)
• Check “flash deals” / VIP early access for limited‑time steep markdowns (ZALORA, Lazada, Pomelo all run these). (ZALORA.sg)
• Compare final price (after vouchers, shipping, returns policy) — sometimes a slightly higher discount on one site is offset by shipping or tough return rules.

If you want, I can:

• Check current active promo codes and the best live deal across ZALORA, Lazada, Shopee and SHEIN right now, and give the single best purchase route for a specific item or brand you have in mind. (This would require me to look up live promos.)