To write you must make time for it. Set aside a specific time of the day, make sure you show up, and be sure to put your fingers on the key board. It sounds simple, right? It is a lot harder than it sounds.

First, make sure you have a designated area for writing. Somewhere quiet and free from distractions. I do not like cafes, I do not like writing on the bus going to work. This might work for you, but for best results, I recommend you set up a writing space, have your desk clear, avoid looking at youtube and face the empty page. Breathe. Write carefully, aim for a target amount of words and keep to it. Training to write well is the same as achieving any goal. Be there every day, put the hours in and clear your mind of distractions.
Treat your writing as importantly as any other aspect of life that you wish to succeed in, be there for your characters, be there to put words on the page. If you miss one day, try to make up for it the next, do not let the writing slip away from you.
Most of all think carefully about your work, read it through, edit it, read the work of other authors. Always try to improve, always work hard. Be a better writer than you were yesterday, show empathy towards all and search your soul. Ask yourself, am I being honest in my writing? Am I adding something of value to this blank page? Do I love to write or am I hoping for fame? If you are hoping for fame, invent a cure for cancer