Tarshis, Barry. Try reading out loudwhich forces you to say each word and also lets you hear how the words sound together. If you know that you have an effective way to catch errors when the paper is almost finished, you can worry less about editing while you are writing your first drafts.
The important thing is to make the process systematic and focused so that you catch as many errors as possible in the least amount of time.
Proofreading marks are traditionally written in red ink for better visibility. You should proofread only after you have finished all of your other editing revisions.
For additional tips, see our handouts on understanding assignments and developing an argument.
Separate the text into individual sentences.