Stuck on a certain problem or document? If your computer is always "online," consider temporarily turning off your internet connection while concentrating. Maybe even turn off the cell phone.
Recently I was working on a christening record from the 1870s. It was written in German and mentioned two families. The temptation was to start surfing for information on the families before I really completed my attempt to translate the document.
Sometimes it is good to brainstorm and jot down ideas one after the other when you cannot immediately do some of them. Being able to search immediately can easily get you distracted and cause you to lose focus on what you were originally trying to figure out.
Without constant interruption or the temptation to be distracted I was able to concentrate on my document, read it as best I could, and make a long list of ideas for how to follow up on what it told me. Then, when I was out of ideas, I got back on the computer and started working on my list, one item at a time.
It helps a lot to be focused.