I am frustrated. I need to know how everyone is learning, do you watch someone doing the experiment? Does someone observe and correct you? How physicians master research especially bench research ?.
Learning research is the same thing as mastering "common" skills. It is not learnt overnight., it may take months to years. I think the best way, would be mentored by a researcher/scientist thru internships, trainings etc. From there, you will know your strengths and weaknesses in terms of research. You will know which knowledge you need to enriched and interests you want to focus.
The concept of research is broad but from your question I am assuming that you are asking 'how can you develop your own craft skills' rather than the research methodology. These are very different, as the ability to complete an experiment does not explicitly or implicitly infer that the researcher understanding the methodology behind the experiment.
With reference to mastery this can be a cognitive process (thinking and reflecting) or a kinaesthetic process (doing and practicing). It works best when both are combined. This is all linked to theories such as Vygotsky 'zone of proximal development.'
In my case, I had chosen the research interest according to my lab setup. Then I was hardly determined to read many research papers regarding that topic. In the meantime, I had written 1 review paper "https://www.researchgate.net/publication/270961590_Microbial_biofilms_in_seafood_A_food-hygiene_challenge".
By completing that, I got many ideas, found lots of protocols for my research. And also I watched youtube and ask google when I didn't find any mentor. Though I am still learning how to research but above-mentioned process helps me much to become an independent researcher.
Article Microbial biofilms in seafood: A food-hygiene challenge