Planning a shop build, any suggestions?

As mentioned above, add LOTS of outlets and lighting. If you are welding or heating, make sure your service will handle as much 220 as you need. If you have a compressor add plumbing so you can locate drops throughout the shop. Insulate and put plywood on the lower walls. A bathroom is a VERY nice upgrade. Definitely add the lean-to's - there is no such thing as a shop that's too big. Being able to get stuff out of the weather is a godsend. A pure luxury I added this year was a mini-split so I have heat and A/C in my shop. It's almost indecent how nice that is. Good luck, and post lots of pictures!