Steven Kotler in his book The Rise of Superman specifies that people procrastinate activities for 2 reasons, first because they are too easy and do not suppose a challenge for us, which is why our brain rejects the option of wanting to start something that really does not represent satisfaction. Or the second reason, when our brain feels completely intimidated by the activity by feeling that it is going to suffer, either because the activity is a much higher challenge than which we feel capable, or because we know that somehow that project reveals a facet of ourselves that we don't have a desire to explore.
Having that knowledge the first thing that you should do is identify which one is the reason you are procrastinating the task that you should be doing, and depending on that you could trick your mind, if your task is too boring, make it spicy, for example, if you have to write a user manual, try to write it giving yourself a challenge or promise yourself a nice reward after the work is done.
In case that the root of your problem to begin or focus in your work is because you feel inadequate or is too complex, nothing like breaking it down and make a list of those little and simpler tasks. And always imagine how is going to feel the future you, when he/she had to deal with all the delayed work that now has to do it in a rush manner. But if this doesn't do enough you always can implement these 5 tips:
Go to walk for at least 15 minutes, jump a rope, or just swipe your room but get away from the thing that is distracting you (in many cases social media), you need to cut that rush of dopamine that your brain is getting from the distractor object because your task in comparison is a pain.
Make a schedule for every activity you want to do and make sure to include the leisure ones too, that is the way you can motivate yourself giving that treat time.
If you are in the middle of an activity that you are stuck for more than half an hour and you are suffering, ask for help if you can, don't let that the difficulty demotivate you, because hard has to be in a sweet spot, can't be as easy that is boring or as difficult that demoralize you.
Make yourself accountable and daily give your list of activities to a friend, a coworker or a family member that evaluate the fulfilment of your commitments.
Finally, count in an audible voice from 1 to 5 and promise yourself to start your task at that 5 sound, you need to begin to trust in the promises that you do to yourself, and treat your time with the same diligence and respect that you treat the time of others.
I hope that this might help someone and thank you for reading!!