shake up vs fluff up

shake up and fluff up both are verbs.

Word	Noun	Adjective	Verb	Adverb
shake up	No	No	Yes	No
fluff up	No	No	Yes	No

As verbs, shake up and fluff up are synonyms defined as:

Other synonyms of shake up include plump up.

shake up (verb)	fluff up (verb)
make fuller by shaking	make fuller by shaking
change the arrangement or position of
stir the feelings, emotions, or peace of
shock physically
shake; especially (a patient to detect fluids or air in the body)
organize anew