Phillip Lim mixed streetwear with a large dose of preppy at Paris fashion on Thursday while Damir Doma and Issey Miyake turned to nature for inspiration.
Lim said his collection was all about mixing up influences to put his finger on what "boys are really wearing right now".
The US designer kicked off his show on day two of the men's collections with a pale blue and grey check suit teamed with white sports shoes and high-necked black shirt.
Other looks for spring/summer 2015 included shorts and an asymmetrical top in large white check and tartan worn with long white socks.
"It was street-prep. It was prep's influence on street urban clothes... I wanna really polish streetwear up," he told AFP backstage.
Lim said he drew on masculine codes and patterns for a "spirit of youthful elegance".
"Streetwear is permanent now in men's fashion. Instead of just making the street, you know, bring it up," the designer added, dressed in one of his own boilersuits.
At Issey Miyake, designer Yusuke Takahashi was inspired by a holiday to the Palau island chain in the Pacific to produce an environmentally conscious collection that delighted marine conservationists.
In contrast to Raf Simons' sombre, prison-chic collection on Wednesday, Takahashi sent out smiling models in joyous clothes.
Squids, jellyfish, pineapples and dragon fruit popped up on garments, giving the collection a playful, pop art feel.
'Polishing up streetwear'
"It's a nice present" from Issey Miyake, Claire Nouvian, founder of marine conservation organisation Bloom, told AFP at the show.
"The depths (of the oceans) are a very beautiful place, but also fragile and devastated by deep sea fishing," she said, adding that she hoped the collection would help to "sensitise" people.
Croatia's Damir Doma also turned to the natural world for inspiration.
The designer said nature and its "profound symmetry as well as its endless irregularities" set him thinking about pattern and texture.
The collection focused on the balance modern men have to strike between design and practicality, formality and casualness, he said.
"It's a kind of symmetry askew. It's something beautiful that you can find in butterflies and flowers... which we tried to transfer into fabrics with laser cuts and the dotted prints," he told AFP.
"It's about the everyday rearranged for the modern man... (who is) a creative sort, a very sensitive person," he said.
Doma added that his jackets aimed to create a relaxed silhouette rich in both fabric and colour combinations.
Examples included a "sea deep blue" and an "unusual violet" that looked like the sky at dawn, he said.
Elsewhere, veteran Japanese designer Yohji Yamamoto's latest collection featured rich tapestry of floral patterned fabrics.
Jackets came with asymmetrical flaps or oversized white patches while trousers were voluminous, some with buttons down the side.
All were teamed with flowing scarfs, hats or headbands and very wild hair.
Five days of men's fashion for spring/summer 2015 wraps up on Sunday, followed from July 6-11 by six days haute couture collections.
AFP, photo by damirdoma.com