I always try and leave the garage in a state that when you open the door it looks like you can get on and have made progress. Spending the first hour trying find grinding discs and a spanner slows me right down and takes the edge off making progress
Ah now this is a good time to impart some advice.
If you have a spare couple of hours and you are not wanting to work on the Mini, start making something that will help you in the garage, something that will avoid all of the searching round for stuff.
I did tis because i had exactly the same problem and as i have to use my garage as an entrance/exit to my flat, it has to be kept tidy.
I made a small trolley out of a vegetable rack which is on castors, has a plastic tool tray in the top and holds, spot weld drill, Grinder, grinding discs, flap discs etc, Zinc Primer cans, a few common drill bits and attachments and its ideal, i can find everything straight off.
I also made a trolley for my welder which holds a big gas cylinder, the welder itself, has storage for shield, cables etc and is portable.
With just these few things, i can go from a tidy garage to full flow working in a few minutes.
Give it a try, works for me 
Ben