For the rest of us, outside accountability in some form or other is usually necessary, but you have to pick the right form. If you and your bestie will just keep letting each other slide, that’s not the right plan to go with.
You might need someone a little outside your comfort zone that’ll make you feel scared to report “No progress” back to.
For others, having someone warm and supportive is imperative. Scary deadlines and the possibility of disappointment just engenders further procrastination or even freezes them up.
Some people do really well with gamification apps, including the ones where you have to put down money and don’t get it back unless you stick with your plan.
Or maybe you need tangible rewards, like a nice meal out or that new pair of shoes… but only after you complete a task or set of tasks.