It is essential that you make your plan realistic. A task may seem like it will only take an hour, but you have to consider the possibility of distractions, emergency phone calls, or having to deal with unexpected issues in the office.
This can easily result in you falling behind schedule, and having to work late to be able to honour your commitments and keep to your deadlines. To prevent this from happening, you need to expect the unexpected, foresee the unforeseen and anticipate distractions.
However long you think the task will take you, double it, and allocate this amount of time for it in your plan/diary. This will mean that you can still meet your deadlines even if you find yourself getting side-tracked by other tasks.
Contributor: Grant van der Harst from angloliners.co.uk