When you are undecided, you are stuck with off and on willpower - and that doesn't work.
The actual best way is to decide 100% once and for all and to make it a part of who you are.
Watch, about a 15 minute Tedx Talk: The 100% Rule - Benjamin Hardy
Then think of some things that would totally uplevel your life and have you let go of issues/problems and then ask "What would happen if i did this for the rest of my life?"
This is what will transform your life, not some quantum leap miracle solution offered by self help sellers!