Make sure to have a yeast backup. I don't so starters.
Make enough RO water for the brew.
Weigh out grains (crush what isn't already).
Measure out any wet/dry additives (DME Malto-dextrin-molases,etc.)
Weigh out hops.
Measure out minerals for the water.
Make sure everything is clean (I sanitize it all during the boil).
Set up mash tun.
Do a test on the immersion chiller to check for leaks.
Make sure there is enough propane
, anti-foam, irish moss and Starsan
Print out the entire recipe and method as a check list.
Might seem a bit extreme but it sure makes most brew days go smooth and problem free.