Q: "I'm struggling with what to focus on. It's seems like every time I'm in the middle of a project, I get distracted by something new on the horizon. How can I keep my focus in the middle of a project?"
A: "For me it's two things.
The first is self-discipline. If you're going to get anywhere in life, you need to build up a level of self discipline, but in order to achieve self-discipline you also need to build up your level of focus.
Being able to see a job through is an extremely important skill that will have an exponential affect on your growth and success as a designer.
To increase your focus, make sure you give yourself the best chance of being successful. This means minimising distractions, being well rested, hydrated and eating the right foods. Allocate blocks of time for work and explain to those around you how important it is to be left alone to work.
The other is to have a series of fun side projects that provide breaks from your main project. By taking regular breaks from the main project, you are able to keep things fresh. These side projects don't always have to be more jobs, instead make them useful, such as learning something new, watching a great film or educating yourself on emerging trends in your industry.
Just don't spend too much time away from the job at hand!