It's so rewarding to reach the end of a project that you've devoted so much time to. It's hard not to get caught up in the can't-wait-to-submit excitement, HOWEVER, we cannot stress enough that you can never proof your pages too many times!
When you've been staring at the same pages for months, it can be tough to "see" things that need correcting. Asking someone else to look over your pages for you can be a big help. By using the 'share' icon (found in the top bar, looks like a square with an arrow in it) you can create a PDF to share with all those willing to proof your pages. Print or email the PDF file, whatever process makes the most sense for your situation, then ask for a list of potential edits your helpers find.
Once you've had a chance to take a little break from your own pages, go back and start looking at your layouts in a different way. Think like a designer as you flip through pages. Are elements lined up? Are all of your headlines the same size and font? Are any portraits covered by candids or Accents? Are there any warnings (You'll know because elements will have red or orange frames. Click on the ! in the corner for more information.)? Take the time to correct any issues you find–then go through pages again the following day. You'll be glad you did!