What are you planning to do?
Before you sit down at your desk, open your laptop, or pick up your phone, decide what you want to do first.
Every day we're bombarded by advertising fighting for our attention. That's on top of the notifications, interruptions, and latest and loudest "emergencies" that you have to contend with.
When you become aware that you’re not working on what you’d intended to do, stop. Stand up or take a break if you need to. Then get rid of any distractions, decide what you're going to work on, sit down and start again.
It can be hard enough to maintain your focus on one goal for a day, let alone a year, but you can always be definite about what you want to do before you sit down at your desk.
Clear intentions lead to completed actions, projects and goals. Having a complete, up-to-date task list split up into discrete, explicit actions helps too.
It's too easy to lose time going down rabbit holes (unless you already had an action on your task list to go down there). Get clear on what you intend to do and get back on track.