spiff up vs spruce up

spiff up and spruce up both are verbs.

Word	Noun	Adjective	Verb	Adverb
spiff up	No	No	Yes	No
spruce up	No	No	Yes	No

As verbs, spiff up and spruce up are synonyms defined as:

Other synonyms of spiff up include slick up, smarten up, spruce, titivate, tittivate.

spiff up (verb)	spruce up (verb)
make neat, smart, or trim	dress and groom with particular care, as for a special occasion
	make neat, smart, or trim