Rhyming reduplications
Examples: claptrap; fuddy-duddy; herky-jerky; higgledy-piggledy; hobnob; hodgepodge; hurly-burly; mumbo-jumbo; namby-pamby; nitty-gritty; pell-mell; tidbit; willy-nilly
Ablaut reduplications
Examples: bric-a-brac; chit-chat; crisscross; dilly-dally; flimflam; flip-flop; knicknack; mishmash; pitter-patter; riffraff; seesaw; shilly-shally; singsong; teeter-totter; wishy-washy