No matter what the task, it is essential to be able to adhere to one's short term goals.

Make sure your goals are realistic and timely. Realistic means a number of things; make sure they actually are short-term, and are not ambitious. It's okay to have ambitious goals, but for an ambitious goal, you need simpler short-term goals. Timely means that they have a set time. This is where most goal setters fail and procrastinators succeed. Procrastinators will often say "I will get it done," but by simply adding on a time and keeping a promise "I will get it done by 8:00 on Tuesday or I'm not watching Matlock." The goal automatically becomes more realistic.
Keep your goals specific, especially when they're short-term. "Get good grades in school" is not specific, neither is "Get good grades in 2nd semester Chemistry." Remember, these are short-term goals, be specific: "On Tuesday, from 8-10 pm, study and complete the homework for Chemistry." In this example, each short-term goal of studying and completing homework builds up to a larger goal of receiving good grades. If you provide loopholes for yourself to travel through, you'll find yourself making excuses to yourself and excepting them. Lay down the law, buckle down and get them done.
Bring something simple with you to track your goals. Some use technology, a palm pilot, a PDA, but this often creates dependencies. It's tempting to utilize the expensive technology you may possess, but often times it's easier to carry an index card in your wallet/purse with the goals written down. The wallet/purse is used as a suggestion because it is something which people carry around with them everywhere.
Make sure you mark off the goals when they are accomplished. This may not seem very important at first, but developing this habit insures yourself that you are actually looking at the list. Often times, these list writers will only look at the list if they're adding to it.

Keep in mind that nothing in this text will make you a better goal-setter; it's all up to you.
Most importantly is developing your ability to keep your own promises. If you're going to set goals for yourself, don't talk yourself out of them no matter how insignificant it may seem. Even if you don't think that overlooking a goal or promise to yourself could be detrimental, the habit which this behavior forms will be.
If the tips contained in this article aren't of help, you may be suffering from a type of procrastination which should be treated like a mental illness. Assess why and how you procrastinate with tools of psychology and/or, ideally, a psychologist.
Having a third party assess you is very useful. Be open to criticism. Often times third parties are more aware of the flaws that are keeping you from getting your goals accomplished than you are.