I am half way through a Blender video series this year where I try to model, mostly Low Poly, stuff as fast as I can during 10 minutes. I do this once a week every Thursday and this week I'll be releasing episode 29.
My original goal was just to do this to practice and improve my own skills. By enforcing a time limit I found that it could improve my quest to find new and efficient workflows.
To my surprised, a great deal of viewers use these 10 minute modeling videos as tutorials because I run Screencast keys as well as voice out all (at least most) the actions that I do. I also end the videos with some tips usually, which is why the videos are often longer than the 10 minute modeling part.
In this video (pardon the intro :) I model 10 Low Poly Cars in 10 Minutes. It's a way to also get the cars in a matching style to one another in an efficient way. I hope you find this useful.