1. Get a piece of paper and a watch.
2. write a descriptive "work" or "task list" of the specific tasks you are most likely to procrastinate on (i.e. homework, piano lessons, house work etc).
3. Make a list of your most desired activities for the day, that have the least likelihood of procrastination, - "rewarding" or "desired activities" (i.e. playing video games, writing hubs, watching TV hanging out with friends).
4. Prioritize your work task list from the least to the most desirable.
5. Prioritize your rewarding activity list from the most to the least desirable.
6. Set a time period for each work task on your task list (i.e. 30 minutes of math homework; 30 minutes of piano practice; 20 minutes of house work etc).
7. Assign a time period for your desired or reward time (i.e. 30 minutes of TV; 1 hour of hub writing; 20 minutes of video games etc...)
8. Make your final task list for the day to guide your activity. Always start with the most difficult and undesired task first and end with the easiest.
9. Make sure that the most rewarding activity follows the most difficult or undesired work task for the day. Make sure that the the easiest work task is followed by the least rewarding, but still desirable reward activity. Your lists from step 2 and 3 should simply align in this way, from least to most rewarding, on both sides.
Make sure that you take a break after each undesired or difficult task and do a desired or rewarding activity right afterword for the reasonably allotted time, from step 3.
Doing the difficult tasks will become easier and easier for you as time goes by because you are structuring your time and because you are using rewarding activities to positively reinforce the undesired activities.
This transfers motivation from the desired activity (playing a video game) to a less desired activity (practicing piano or doing math homework).
Use your watch to measure and to gradually increase your time on undesired tasks and decrease your time on desired tasks (especially unhealthy reward behaviors).
You can also experiment with shorter work and periods and shorter reward periods (20 minutes of math questions and 10 minutes of video games etc) to find what works best for you.
Gradual increases in the time you spend on tasks you would usually procrastinate on will really help stave off the procrastination. Smaller, well reinforced changes over time are best here.
Hope that helps,