First, keep a calendar and actually write down your daily schedule so you don't float off into daydream land. Figure out how much time it takes you to do everything from eating breakfast to picking up the kids from school. You need to write in bold caps: ART TIME and work in time like it is your 9-5 job BECAUSE IT IS!
Second, don't kill yourself just to finish a project. Instead, write down your ideas as they come to you, take little breaks to reflect on what you've accomplished and come back refreshed. You'll be more efficient (make less mistakes and waste less time) if you prioritize and take time out to take care of yourself.
Third, you're not an island. Make sure you connect with other artists and art collectors so that your work actually goes to a good home and you feel rejuvinated because you know you're appreciated. Actually, motivation and good vibes will energize you and give you the extra push you need to finish something in a shorter amount of time.
Fourth, go to bed (no burning the midnight oil). Yes, this does sound counter-intuitive, but really this ties back into not killing yourself on a project and also keeping a calendar. You need to have a "normal" schedule, one that includes an appropriate about of rest so that your next day isn't shot to hell! Truly makes a difference, trust me... I know from experience.
Do you have more suggestions for other artists, please share below!