Planning things. At least per week or per day. Doing it in the easiest way possible - todoist, trello, the simpler app is the better. When I started to plan procrastination just disappeared.
Time blocking is without a doubt my favorite productivity hack. On Mondays I plan what my priorities will be for each day, and the last thing I do each day is timeblock out the following day so I know how my day is going to go, and there are no surprises.
Having an inbox.
Not just for mails, but for everything. Found something interesting on twitter? A movie to watch? A mail to reply? An order to place? Send it to a singular inbox and batch process them, usually on the day/week end. Lets you put away distractions knowing you can come to it later.
Prioritize, prioritize, prioritize. Trying to attack all your tasks at once will leave you feeling stressed out and you'll ultimately be less productive. Set out 5 or so realistic, high-importance tasks to do in a day and leave the the rest for tomorrow - you'll end the day feeling fulfilled and productive :)