some good points in this list of typical mistakes:

The Technical Lead has overall responsibility for all technical aspects of the project – design, code, technology selection, work assignment, scheduling and architecture are all within his purview. Positioned right at the border of the technical and managerial, they are the proverbial “meat in the sandwich.” This means that they have to be able to speak two languages – the high-level language of the project manager to whom they report, and the low-level technical language of their team. In effect, they’re the translator between the two dialects.

via Scott Berkun