No extraordinary result ever came from mediocre effort.
Don't 'just do it.' First, plan it, then do it.
Focus on who you are becoming not what you are doing
Let today be the day you give up who you've been for who you can become.
Success is a process for all of us, and as long as you are making consistent progress towards your goals - sincerely giving your best effort more often than not - then you are already successful and deserve to feel proud of yourself.
Most people's strategy to achieve more is to do more. But when you focus on becoming more, you find that you can achieve more by doing less.