A shopper looks at Michael Kors handbags at Macy's flagship store in New York.

The idea that shoppers won't buy their clothes online has been more than proven to be a myth.

And with growth in the clothing category slower than the overall retail sector, those retailers need to fight for every sale on every platform.

Industry experts recommend a strategy that provides customized products and personalized services both online and in stores.

"What's in the store, on your phone, on your laptop … it's a 360, sort of, surround-sound shopping experience and that's where customers are going," said Matthew Shay, president and CEO of the National Retail Federation, at the group's 2018 Big Show in New York.

Meantime, Amazon has created an overhanging "threat" against the sector that won't go away anytime soon, Don Kingsborough, the CEO of San Francisco-based OneMarket, told CNBC. That's what has pushed some brands to do more and to act swiftly, he said.

"We've seen these trends come and go, but this time retailers are being applauded because they're more thoughtful about where they position themselves and how," said Kingsborough, who also serves as a member of NRF's board.