Research is an interesting topic and something that plays a big role in my life. I like to think that I do research every day.
The most useful thing that has helped me be more productive in uncovering new and interesting things is to do things with a purpose. Research included.
As for the research itself, I use all the tools available to me to answer a question I have. I love using macOS dictionary app to quickly go and read a wiki article. It is amazing how fast it lets me both search for things there and simply explore the depth of the wiki.
For searching, I use:
Google - General / programming related.
DuckDuckGo - Private searches / instant answers / cheat sheets.
GitHub - Software / repos / code search
And of course I love specializing my search to any website I wish. My Web Searches workflow lets me do that with ease and anyone can download it too to get all these search super powers.
There is also absolutely amazing workflow to search various websites with autosuggestions. I highly recommend it. It essentially lets you have powerful search like Google, DuckDuckGo, YouTube and more from wherever you are in your operating system.
It's insane, the world we live in.
We have all the knowledge of every human who has ever lived or lives now at our disposal. Not many people do share all their knowledge in a continuous way like I do here but most people share it through their blogs. Their code, videos, tweets and other mediums.
Google, DuckDuckGo and other search engines are phenomenal in how they solve this problem of trying to access and query all this collective sum of knowledge.
Together with Learn Anything, you have all the superpowers of this world to create anything and everything. Things that didn't exist before. Ideas and thoughts that weren't thought of before.
Prophy - Search research documents.