Approach number one involves tackling the biggest tasks first and getting them out of the way. The idea is that by tackling them first you deal with the pressure and anxiety that builds up and prevents you from getting anything done.
Approach number two involves tackling the tasks you can get done quickly and easily, with minimal effort. Proponents of this method believe that by tackling the small tasks first, you’ll have less distracting you when you do the big ones.
Prioritization relies very much on you and the way you work. Some people need to get some small work done to find a sense of accomplishment and clarity that allows them to focus on and tackle bigger items. Others need to deal with the big tasks or they’ll get caught up in the busywork of the day and never move on.
Some people are in between -- some days ready to rip into massive projects at 7AM, other times feeling the need to clean up the papers on their desk before they can focus on anything serious. If you’re that kind of person, you need to keep your schedule liquid enough that you can adapt.
The prioritization systems themselves don’t matter. What matters is that you don’t fall for one set of dogma until you’ve tried the systems extensively, and found which method of prioritization works for you.
If the system you already use works well, then there’s no need to bother trying others. But if you find yourself prioritizing tasks that never get done, you might need to reconsider which of the above approaches you’re using and change to a system that is more personally effective.