Break each part of a project down to what you can do in one sitting. If any item on your list is longer than 8 hrs, you're probably going to miss it. Also, fi

Break each part of a project down to what you can do in one sitting. If any item on your list is longer than 8 hrs, you're probably going to miss it. Also, figure out how many of THOSE thing you can do in a week (unlikely to get 40 billable hours / week for me) As a general rule, if I'm unsure of exactly how long something will take, I double it, and I'm usually very close, or over the high end. (I'm down currently to only adding 40% more time per each unsure item, which has been very close lately..not that I'm getting faster, I'm just getting better at estimating) Plan time to make their edits (10-20% or more of the project, depending on the quality and robustness of the original spec). Don't take on a project with a hard deadline you can't meet, you will make yourself crazy.