There are 3 main challenges when it comes to productivity:
1) Start: How do you kick off a project, especially when you're full of doubts and feel intimidated by the size of the project you want to take on (small projects may offer little resistance, but they also don't offer enough motivation to complete them. Changing a lightbulb may not take too much time or effort, but it may also not be at the top of your priorities list. Unless, perhaps, it's the last lightbulb that goes out)
2) Persist: Some people get super excited when they start a new project, but they continue starting newer and newer projects without ever seeing projects through. That's because working on the same project can become boring, and the start phase is usually full of creativity and ideation, but at some point you have to turn from "divergent thinking" to "convergent (focused) execution", which isn't all that fun for many people.
"80% of success is showing up." (Woody Allen)
That's because seeing projects through requires keeping at them over the span of days, weeks, months, or years. You have to keep the fire in you alive day in and day out.
3) Finish: Every project needs to have a scope and an end point that signifies its completion. Projects can grow and develop indefinitely, but the scope gives you focus and clarity about what you're working towards. It could be version 1 of what you're building, or you don't intend on making changes to it ever again. I won't likely be revisiting this page to make edits to it, but it's a project with a scope (an article that's at least 200 words, with a point to make).
To complete projects you need to give them scope and work towards completion, eliminating distractions and valuing shipping something more than an abstract definition of perfection.
What do you find yourself stuck on? How can you overcome the obstacles standing in your way at each leg of the journey?
Start. Persist. Finish.