My main task is to advance my research (my PhD thesis). In addition to research, I have some teaching and administrative responsibilities, as well as lectures, seminars and conferences to attend to.
My working hours and my work in general are very flexible. Still, I usually spend my working days at the office, because it sets me limits and a good work-life balance, even though most of the work happens in my head. I usually start my day by reading and answering to e-mails. Oftentimes I also have a moment to read news and articles related to my research topic with a cup of coffee. This gives me a good momentum and allows me to focus mainly on my research for the rest of the day. Because my work is so independent, I like to plan my days/week in advance. In practice, this means 3-5 focus points and perhaps a key theme for the day. This can be writing (e.g. freewriting to boost creativity or focusing on a certain part in a research article), reading, collecting or processing data, or tasks directly related to my research, i.e. developing and using mathematical models. Sometimes I attend lectures or seminars during the day, and every now and then I also teach myself. My work is very multidisciplinary and international, which means colleague meetings and Skype-calls on a regular basis.
I love that I can really contribute to some greater good by advancing knowledge on my research topic. I love the objectivity and the holistic view that research should have: there is no room to sub-optimize or take sides. I also love the flexibility that my work has: I have high control over the big picture and my daily tasks. This way I also feel that I can all the time develop in my what I'm doing.
The independence of a researcher also has its downsides: sometimes it would feel good to have a real team to work with. Freedom also requires creativity in terms of "goals achieved" to feel accomplished, and high self-discipline. The financial compensation is of course a matter of its own. Thus, one really needs to be motivated by the research topic and by the benefits that being a research can offer.
You learn by doing, and you learn each day. This teaches you all of the above, but above all patience. But of course, courses and seminars, colleagues and a good-ol' Google-searching when it comes to the software will take you far, too.