spruce up vs spiff up

spruce up and spiff up both are verbs.

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

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

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

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