I don't post on time management very often as there are a lot resources out there on it anyway but this one issue has cropped up fairly often to people in my life lately so I figured I'd drop this little tidbit down.
However long you think something is going to take you.....ADD MORE TIME!!!
You know the phrase our eyes are bigger than our stomachs? Well the same philosophy can be attributed to our thoughts on how long it takes to do something. When I used to do presentations on organization and the like I would always talk about to do lists to keep you on track but then I would say this: After you write up your to do list for the day - take two items off.
For some reason we think that we will never be interrupted, that every task will go smoothly and quickly and that the ones involving other people - well they must be on the same schedule as us right? NO
Things take longer, interruptions happen, our attention wanders and sometimes we need to wait for a call back or a response to an e-mail. So, plan more time everybody, prioritize appropriately and then you won't feel like you never get anything done the way you intend to.