Can't focus? Try turning off your cell phone, specifically during working periods of 60-90 minutes. You can always check your messages on your breaks and return phone calls within an hour or two.
Just contemplating doing this can bring up all sorts of fears, many of which are irrational.
Ask yourself, "does anyone
really need to reach me in the next 60 minutes? Is that access really more important than the task I'm working on right now, or am I hoping that someone interrupts me with a crisis because that's easier than doing some real thinking on this project?"
I just started this habit recently when working on some writing projects and it has been interesting to note how much more I could focus.
"But what if someone needs me urgently?" I hear you asking. Well it depends on whether you actually have the kind of job where it is important to be in touch 24-7. If you are a doctor, or a customer service rep, this strategy might not be the best way to do your job. But if you are a knowledge worker who needs periods of focus to actually do work without (as many) interruptions, then it can be useful.
If you want complete focus, close all chat programs, unplug your office phone, and even close your email. *gasp!* Heck, if you are lucky enough to have an office with a door, close that too.
Go dark. Not forever, just for 60-90 minutes to really crank out some focused work. (If you go completely unreachable for more than an hour, you may want to consider letting people know, like with an email vacation responder, calling people who might need you in advance, etc.)
We tend to get caught up in multitasking mode so much so that we can't even tell we are stressed out and only responding to crises that come our way. Try turning off your phone or "going dark" for a few hours today and see how it works for you!