Thank you to @lowrahh has put together detailed instructions for Rotten Tomatoes and IMDb:
Rotten Tomatoes
Click “Login/Signup” (PC) or tap “My profile” (mobile) and enter your email address or link up your Google account.
Check your email inbox for the verification email. Click/tap “Verify my email address” and choose whether you want to sign up to the newsletter.
Search 'Our Flag Means Death' or follow this link.
Scroll down or click/tap “Seasons”, then go to “Details”.
Scroll down again to get to the Audience Ratings sections, then click/tap “Post a review”.
Rate each season and describe what you loved about it! Hit “Submit changes” to save. Don’t mention the petition, as it could get your review flagged as spam.
Rate and/or review a few other shows or movies – it’s not entirely clear whether Rotten Tomatoes takes this into account, but it definitely can’t hurt, and leaving a rating only takes a few seconds.
IMDB
Go to https://imdb.com or download the IMDb app on Google Play / App Store.
Click “Sign In” (browser) or tap “You” (app) to create a new account or sign in using any of the other accounts shown.
Check your email inbox for the verification email. Return to IMDb and fill in the code to verify your email address.
Search ‘Our Flag Means Death' or click here: https://www.imdb.com/title/tt11000902/
Give your overall rating for the show.
Go to ‘User reviews’ and click “+ Review this title” (or tap the + on the app); write an honest but positive review (600 characters or more).
Please Note: Do not mention the petition, as it could get your review flagged as spam. If you can’t leave a review yourself, scroll through other people’s reviews and mark the positive ones as helpful/the negative ones as not helpful.
You can also rate each individual episode: select “Episode guide” at the top of the page and rate each one. Find your favorite episode(s), go to ‘User reviews’ and write your own episode review! Make sure you write a unique review for each episode to avoid triggering the spam filter.
Please Note: Important! Rate and/or review a few other shows or movies – otherwise IMDb’s algorithm will give your reviews less weight. The “More like this” section is your friend!
