Many resources that debaters could use are behind paywalls. Most of the extensions here are ones that I only know about for Chrome, but alternatives probably exist for other platforms. However, almost everything should be usable on any web browser. Happy researching!
There are a lot of paywalled news sources. You should try a variety of methods to access them, and figure out which methods work at which times.
Bypass Paywalls extension
This is an extension that runs passively, unlike lots of the fixes on this page. All you have to do is download and install it, and it'll do the work for you. You won't even notice the paywall existed! On the link below, you can see the long list of sites it bypasses.
Some paywalls are bypassed simply by using incognito mode or clearing your cookies. This takes two seconds to try.
In some cases, the article is available online on some blog site that just reposted the article. Take a passage from the article, and try searching it with and then without quotes (if you didn't find it). You may be able to find a copy of the article there.
Copy and paste really fast
On Bloomberg and the Economist, some paywalls take a little longer to load then the article, so refresh the page, and as the article loads, press ctrl-a and ctrl-c really fast, then paste it into a word document (I recommend using the F2 key in Verbatim to avoid weird formatting). Once you try a few times, you should get the hang of it.
The stop loading button
On Chrome (and most browsers), while the page is loading, the button that'd normally reload changes to an X to stop the loading. Similar to the method above, when the page's text has loaded but the paywall hasn't, you can click it to stop loading. These work better if done right after clearing cookies or going into incognito mode.
Outline is a service that aims to make websites more readable, eliminating clutter on pages. However, on certain sites, it works to bypass paywalls. Either use the site below to access it, or put "outline.com/" before the URL.
Archive.org is a site that, as the name suggests, archives sites. The most applicable tool for us is the Wayback Machine, which lets you view old versions of sites. As time goes on, sites go offline and some URLs you find may be unusable. Pasting them in the Wayback Machine, if they were archived, lets you view an old version of the site.
Apart from being the best adblocker out there, uBlock Origin lets you bypass the rudimentary paywalls with its zapper tool. Take, for example, this article from Foreign Policy, behind a simple paywall. Click on the extension, select the zapper tool, and use it to get rid of the paywall. (This article's paywall is a bit persistent, but if it pops up again you can just use the zapper again.)
Read Across the Aisle
Read Across the Aisle is a project to get people to escape their news bubble, but the point here is that it includes a guest pass to the Wall Street Journal, which can be renewed for free.
If you're linked to one of their articles, i.e. accessed it through clicking a hyperlink, it pretends to have a paywall. Just paste the article title into Google and open it from there, it should be available.
Some paywalled sites, notably Foreign Policy and Bloomberg, have their un-paywalled pages cached by Google. To see these, Google search the article and below the link you usually click, there should be a green URL below it. Click the down arrow at the right of the URL, and click cached to view the article.
Academic sources from published journals and research are probably the best sources for you to use. However, huge amounts of research are paywalled by publishers, charging exorbitant prices for a PDF. Use these methods to access them for free. There are fewer methods than for news sources, but that's partially because of how effective these tools are.
Lots of academic articles are paywalled on some sites, but available completely free on others. Most of the time, this is on some obscure academic site or the personal page of researchers, which aren't easy to find yourself. Unpaywall is an extension that detects these alternative sources for you, giving you the ability to access those PDFs with a single click. This extension lets you access any available papers that are legally posted, and is extremely easy to use - if the button is green, a legally free version exists; if it's gray, it doesn't (and you should use another method).
Sci-Hub is an extremely convenient service for accessing academic articles. In most cases, you can simply paste the URL of the article or the DOI into the search field, or paste it after "sci-hub.tw/" to access a free PDF. Some articles are unavailable, but from my experience, those are extremely rare. (NOTE: Since Sci-Hub is constantly under assault from publishers, you may have to change the "tw" in the url to something else later on, use the URLs in "availability" below.)
To make Sci-Hub even more convenient, I recommend setting up a custom search engine in Chrome. From the settings menu, scroll down to "Manage Search Engines" and add one with the "Add" button. Name the search engine whatever, like "scihub," it's not important. For the next field, you need to set the keyword to something simple (mine is "sh"), and use "http://sci-hub.tw/%s" as the URL in the next field. Now, in the Chrome search bar, you can simply type "sh" and hit tab to search within Sci-Hub, pasting whatever DOI or URL you need.
To make Sci-Hub EVEN MORE CONVENIENT, you can even install a custom Sci-Hub extension! If you don't feel comfortable downloading files from a random site, you don't have to, but given that Sci-Hub isn't on great terms with the law, you'll have to sideload the extension. You can download it from here, and extract it from the zip file. Go to chrome://extensions/ and click "Load unpacked," selecting the folder labeled "scihub extension." After it's installed, whenever you're on an academic or research site with a paywall, clicking the extension's button should automatically append "sci-hub.tw" to the URL, sending you straight to the page.
Extension: https://github.com/allanino/sci-hub-fy, see for more information on the extension
Library Genesis, or libgen, is a site for accessing academic articles and books, which is more complicated than sci-hub. You can use many of the same functions through the search, such as pasting in the DOI, but it's expanded to accept things like ISBN, authors, publishers, etc. Unfortunately, I can't fully explain many of its features, but even the ones that I've found are very helpful. When you're taken to the page for a book or article, click one of the mirrors to go to the download link.
This is probably the tool I use most outside of debate - for books you need in class, test prep material, or stuff you just want to read yourself, libgen probably has it. I haven't bought a book in a long time, since nearly everything is available through libgen.
HeinOnline is a legal database with a huge number of papers on law and politics, quite helpful for debate. I haven't found a workaround for its paywall, but the NSDA gives you free membership to the database. Simply log in to your NSDA account, open the link below, and then open whatever paper you want. Unlike many of the NSDA's resources, this does not require a purchase of their resource package or even a confirmed school affiliation.
Email the author
The authors of articles are people too! They are probably excited to hear that people are using their research, and in many cases are happy to help you learn about their topic. In some cases, they can point you to places you can find PDFs for free, or answer the questions you had about their topic. I've never had a bad experience with contacting an author; they can direct your research and help you get a glimpse into how the resolution is perceived by the actual academic community.