For me, it is very hard to kept focus once I get distracted by something or someone. So step, I listen to music that motovates the project I'm working on and if that dosn't work, I try to remember the image of the end result, the feeling of finshing, submitting for everyone to see and being commented on it but if that all fails, I just do something else then come back to it later, if I don't forget about it.