Coney Hatch released “Friction” in 1985.
The song “Monkey Bars” has a riff and vocal melody that sounds like a Beatsie Boys tune called “Fight For Your Right (To Party)” which came out in 1986.
Kingdom Come released their self titled debut in 1988.
“Get It On”, takes the entire chord progression from “Kashmir” and “What Love Can Be” takes from “Since I’ve been loving You” and “The Rain Song”.
Bon Jovi released Slippery When Wet” in 1986 and Desmond Child just took the music and melodies of a song he wrote for Bonnie Tyler called “If You Were A Woman (And I Was A Man)” and used it for “You Give Love A Bad Name”. Then Belinda Carlisle and her team came out with “Heaven Is a Place on Earth” a year later.
Basically be influenced and take what came before and make it better.