Self-discipline

"For God did not give us a spirit of timidity, but a spirit of power, of love and of self-discipline." ~ 2 Timothy 1:7

Self-discipline. How does that work? If you lack it, how do you learn it? Pray a lot? Read a book? Create a schedule? Berate yourself into action? Or maybe it's about forcing yourself to do stuff even when you don't feel like it? Okay so some of those questions are facetious but you get the point right? I'm wondering how to cultivate self-discipline.

Then I read 2 Timothy 1:7 where I see that God has given me a spirit of self-discipline. What does that mean? Because the Holy Spirit lives in me, self-discipline is possible. It's a fruit of the Spirit-filled life (Galatians 5:22-23). But why then do I feel a lack of self-discipline in certain areas of my life? Is it fear? Laziness? Lack of trust in God? Lack of reliance on Holy Spirit?

Always the questions without answers. I am seeking wisdom from the Lord and I believe He will supply it (James 1:5).