block out vs sketch out

block out and sketch out both are verbs.

Word	Noun	Adjective	Verb	Adverb
block out	No	No	Yes	No
sketch out	No	No	Yes	No

As verbs, block out and sketch out are synonyms defined as:

block out (verb)	sketch out (verb)
plan where and when songs should be inserted into a theatrical production, or plan a theatrical production in general	indicate roughly
indicate roughly
shield from light
prevent from entering