It can be helpful to use a checklist when proofreading or self-editing a manuscript.

First, ask yourself if you are too tired or distracted by other factors to give the work your full attention.  If so, and you can, wait until later when you are more rested or less distracted then check:

• Are all the character and place names spelt correctly and consistently?
• Is the capitalisation consistent?
• Is there a change in tense in a sentence for no reason?
• Has a plural verb been used, mistakenly, with a singular noun or vice versa?
• Are any ellipses spaced consistently?
• Is any punctuation missing?
• If a character is speaking over multiple paragraphs, are the closing speech marks placed only at the end of the last paragraph of dialogue?
• Are the conventions of your English dialect being followed?

This list is not exhaustive, but is a general check of the manuscript for spelling and grammar.