Temperature   The best layout investment I've ever made was replacing my old tilt-up wood garage door with a sectional insulated door. Not as cheap, but worth every extra penny. The new door has reduced the temperature swing in the garage by 10-15 degrees per day, making it a more pleasant place to be more of the time.   Because my garage really bakes in the afternoon sun, I installed an attic gable fan inside the garage, exhausting to the outside. This helps draw in cool air in the evening and early in the morning. It was a little work figuring out how to mount the unit against the inside wall, but it's been a big help.

Click image for fan notes in .pdf file

Use the "Big Aisle"   Too many designs simply split the garage in half and use one section for parking the car and the other for the layout. Look at ways to cantilever part of the layout over the hood or even over the roof of the parked car. If you are willing to stipulate that any serious operation or construction is done while the car is parked elsewhere, the resulting designs will provide more in the same space. Use that "big aisle" where the car parks to best advantage in your design. I wrote about this in detail in the LDJ article.   In this rough sketch of my overall layout, the long horizontal peninsula will extend over the hood of the parked car.