Get 30% off your Ola rides. Apply coupon SYD30 to redeem. Valid for 15 rides, capped at $8 per ride until 17 Feb 19.
Take a screenshot when booking - have often found they charge more after the ride and have to contact them for a refund, but can still be cheaper than Uber.
Also $25 flat airport rides: https://www.ozbargain.com.au/node/436558