How to start a project/ painting? Sometimes finishing a project becomes a task and I will share my experience that has helped me stay on track. 

Let’s start with, being passionate helps. 

• Pick one project that you feel passionate about. Dedicate a particular time every day to the task. Take weekends off, but stay on track.
• Use an analog timer and set the time for 30 minutes or one hour that you have dedicated to this particular task. Don’t check your social media or even check time.
• Experiment with several time management techniques. Make an agreement with a friend or your partner to keep a tab on you at the end of the week. Report your work to them. They just have to read it to you, not critique. They can also respond a little which can motivate you to carry on or help you with any input. I do that with my friend. We tell each other about the project we are starting and then keep reminding or asking about the progress. It motivates you. 
• Taking time off consciously even if you are not working on a project. It will give you a fresh eye when you go back to the project and also give you a chance to do something that you enjoy other than art like reading a book (although I am not much of a reader), going for a walk, playing a board game or just sitting and not doing anything (which is my favorite ). When you consciously take time off, you are not beating yourself or feeling guilty of not doing your work (which most of us feel when we are behind). You have chosen to do that. In this case I also like to meditate. Just sit, close your eyes and not do anything. Be in that moment. No distraction, no rush, nothing on your mind. Everything can wait. It has helped me a lot with my focus on what I really want to do.  
• Keep a  notebook with you all the time or be ready to write in your phone notes which I do. To do what? Write an idea whenever it comes to you. Even if it’s just a word or line. Like this particular article I wrote in breaks and not in one sitting. Just do bullet points. Also sometimes I write about what I want to draw next or how I am feeling and that feeling would be shown in my artwork. Reread your diary at the end of the day to see what you have accomplished.
• Make daily notes of things you have accomplished, make a to do list , put it on the fridge. Make a list of places you want to send your work to. I have made an excel sheet for that and I cross it off or mark it send to keep myself on track. 

Changing behavior is hard. Be aware of your habits. Habits are not good either bad or good. Doing things consciously and being aware of what you are doing is something you want to accomplish. Something that is taking your time and not productive is better to spend on something else. I think that kind of sums up a lot of things to do and not do to keep you focused and do what you love.