These days I append either "wikipedia" or "reddit" to most of my Google searches in order to get useful information. There's so much SEO'd garbage out there, but Wikipedia remains a breath of fresh air.
However, it's an excellent source for finding information about hobbies and niche topics. The culinary subreddits have great recipe advice and I'll often go there to find best practices for food safety or unfamiliar techniques. Appending "reddit" to the end of my search means I don't have to sift through hundreds of SEO'd blog posts with questionable advice! For the time being, people don't SEO their reddit comments.
Now that I think of it, I actually do this quite often--Google really isn't what it used to be.
In cases where you aren't searching directly on one of the supported sites, and would prefer google's algorithms instead of ddg's (or reddit's), all you have to do is add !g. It's a lot easier than trying to get google to do direct searches (using site:) or search on ddg (I don't think google has any shortcuts for redirecting to search on another search engine).
Firefox setup:
- Go to the page with the search you want, e.g. wikipedia.com
- Right-click the search box
- "Add a Keyword for this search"
- Type your "keyword" e.g. w
Now any time you want to search wikipedia, go to the URL bar and type w plus a space first, then your search term.
Chrome setup:
I haven't used Chrome for a while but it also has this feature. You add "keywords" for your site searches somewhere in the settings instead of via right-clicking the search box, but the usage once it's set up is the same.
I just came up with this example on the spot, searching wikipedia for "inventor of paracetamol", the first result on wiki search is "Polymorphism", then "Diphenhydramine", then "List of Suicides", then "Menstruation"
Searching google for "inventor of paracetamol wiki" links to the wikipedia Paracetamol page subsection History