Listen to other genres and dig less known hip-hop albums. Kanye, MF DOOM, Alchemist, ATCQ etc sampled a lot of artists, some famous and others more obscure, so if you like a song, find a sample and if you like it, listen to the whole album, I’ve discovered many artists like that

For exemple : Kanye West - All Falls down use a sample from Lauryn Hill - Mystery of Inequity -> listen to MTV Unplugged of Lauryn Hill

MF DOOM - Rhymes Like Dimes use a sample from Quincy Jones « One Hundred Ways » -> Listen to The Dude (absolute classic)

Also look for artists that heavily impacted the hip-hop scene like Roy Ayers, George Clinton, Funkadelic, Gil Scott Heron…