I can safely say that all of the strategies that I suggest have been used successfully by the people whom I serve in my practice and through my writing.
Some of them may work for you, and some of them may not. The only way you will find out what works best for you is to try out the strategies that you think make sense in terms of how you think you operate best. Then give yourself sufficient time to experiment. After a sufficient period of time, assess what is working and what is not working. When necessary, modify what you are doing.
The key to successfully reaching your goals is acknowledging that not everything you try will work well for you at first. Knowing that you will certainly have occasional setbacks and being able to bounce back from them will keep you from becoming stuck.
It is useful to approach new strategies with an experimental mind, such as in the example below.
I am committing to writing on Monday, Wednesday and Friday for 2 hours. Rather than scheduling the time, I am going to be more flexible by writing when I do not have fixed appointments for a minimum of ½ hr at a time. The total time for each day will add up to 2 hours. I will try this for two weeks before I reassess whether this strategy is working for me and what I may need to change.
Please do not try to fit yourself into a box. Rather, work with your strengths. Working with your ADD, and not against it, will require experimenting.
Oh, and have fun learning!