Write or project a paragraph on the board. Go through the paragraph sentence by sentence, calling on different students to read each sentence aloud and then find the errors. Model and explain the use of standard editing marks, such as carets for inserting words or punctuation and drawing three lines under letters or words that should be capitalized.
Create proofreading worksheets by writing or copying passages and introducing several spelling, punctuation, grammatical and word choice errors. Double-space passages so students have plenty of space to make edits. Make it easier by telling students how many of each type of error they can expect.
Assign partners or put students in small groups and give them a long passage that includes several errors. Give the groups two to five minutes to find as many errors as possible. After time is up, review all the errors and give a small prize to the group who found the most errors.
One important step in proofreading is reading your work out loud, because it's easier to hear grammatical and word choice errors than notice them on paper. Read a passage to the class and have students raise their hands when they hear an error. Call on a student to have him explain the error to the class and offer a correction.
Homonyms are words that sound the same but have different spellings and meanings. Spell-check won't catch these errors. Review commonly misspelled homonyms with students, such as affect/effect, they're/their, you're/your and discreet/discrete by writing both words and definitions on the board and calling on students to make up sentences for each definition.