Write down some realistic things you want to do today that you might avoid. Do this as early in the day as possible.
Before you make a decision which will avoid doing one of those things you wrote down, stop, think about it for 60+ seconds. Usually these decisions are done just like instincts without thinking: "hit next episode on netflix", "read this HN link", etc.
In that 60+ seconds, suggestions:
1. Decide to start on the thing you'd rather avoid for just 5 minutes, then you can quit if you want.
2. Imagine your future self looking back on your decisions.
3. Remember how this thing ties into long term goals.
4. Plan a reward for yourself if you do the thing.
5. When negative thoughts or feelings happen, accept them, don't believe them or give them any more power, see them from the outside.