* Not having multiple clients lined up (in Round 1 of my company I made this mistake and had to get a "real job" for a while).
* Not starting early and having to pull all-nighters as deadlines approached.
* Not communicating with clients on a daily basis (this also helps to keep you from procrastinating).
* Not starting on your crazy side ideas/weekend projects as soon as possible. The longer they sit on your to-do list, the more they'll bug you but also the less likely they'll get done. If you at least get them to a prototype stage, you won't feel like you missed out even if you decide not to finish them.
> * Not starting early and having to pull all-nighters as deadlines approached.
It is easy to beat yourself over this point, but procrastination is extremely common. I'm highly guilty of it. In school, work, and life, without hard deadlines approaching, it is too easy to wait until the last minute and be forced to pull all-nighters.
* Not starting early and having to pull all-nighters as deadlines approached.
* Not communicating with clients on a daily basis (this also helps to keep you from procrastinating).
* Not starting on your crazy side ideas/weekend projects as soon as possible. The longer they sit on your to-do list, the more they'll bug you but also the less likely they'll get done. If you at least get them to a prototype stage, you won't feel like you missed out even if you decide not to finish them.