What is the best advice or approach for training discipline?
The best approach for training discipline, is the one you give yourself, if you are determine in what you're doing, you give yourself a honest advice someone can't give to you.
How do you build consistency and self-control over time, especially when motivation is low?
A self control, is something that you can achieve through a decision taker and limitation of things you do...If your motivation is low, the only way you can skyrocket your motivation feeling's, is to look upto what you have achieved in your time, and also compare with other people, what they have achieved, especially people who is doing better than you.
Any practical tips, habits, or personal experiences would be greatly appreciated.
Theirs no tips that's better than the one you derived by yourself, but remember that determination is the key to success, when you're discouraged you can't achieve your objectives.