Focus cannot be maintained for long hours without some sort of intervention from stimulants like Caffeine. There is a limit to our biology. I like to use Yerba Mate (http://www.theroadtosiliconvalley.com/personal-development/y...) to help with long focus. For me, it works better than tea/coffee.
Once you are focused, choose your battles (as mentioned above ref Peter Drucker). Actually you should choose your battle well before you begin.
I find that whenever I get distracted by a thought, an idea or something else that needs to be done I try to remove it from my head by offloading it into a trusted source. This allows me to continue focus on what I'm doing knowing that "later" I can come back to it for review/pick it back up. This is also what the GTD method teaches you. I use an iOS app called GSDfaster => http://www.gsdfaster.com/ - note this is an app I initially built for myself to solve this need.
As some have stated above, sometimes the day feels like crap maybe due to lack of sleep or whatever. Or maybe it was a crap start to the day. It usually means you got wedged into a bad mood. It can last few hours if you don't find a way to get out of it. What works for me is usually a 1 hour walk, bike ride or a gym session. Gym session is the winner here to wake you up both physically and mentally releasing endorphins and "restarting" the brain in a better more focused mood.
Once you are focused, choose your battles (as mentioned above ref Peter Drucker). Actually you should choose your battle well before you begin.
I find that whenever I get distracted by a thought, an idea or something else that needs to be done I try to remove it from my head by offloading it into a trusted source. This allows me to continue focus on what I'm doing knowing that "later" I can come back to it for review/pick it back up. This is also what the GTD method teaches you. I use an iOS app called GSDfaster => http://www.gsdfaster.com/ - note this is an app I initially built for myself to solve this need.
As some have stated above, sometimes the day feels like crap maybe due to lack of sleep or whatever. Or maybe it was a crap start to the day. It usually means you got wedged into a bad mood. It can last few hours if you don't find a way to get out of it. What works for me is usually a 1 hour walk, bike ride or a gym session. Gym session is the winner here to wake you up both physically and mentally releasing endorphins and "restarting" the brain in a better more focused mood.
GOTO Line 1.
Hope this helps :-)