Run in fresh water to flush out salt if used in salt water. Also wash down outside thoroughly and dry ... wax polish if you love it that much.
All routine service items. See
http://www.evinrude.com/Content/Pdf/en-US/PressRelease/maintenance_schedule.pdf
Grease or oil all external moving parts. Prop splines too
Note any signs of water ingress when draining gear case. Now is the time to investigate and rectify if necessary, before refilling with correct oil.
Good idea to put stabiliser in fuel for the last run, other wise drain fuel system and carbs. ( best drained if possible anyway)
Fog engine with fogging oil on last run. Spray into intakes or via Schrader valve if fitted with one. (Can use 2 stroke oil in a trigger spray bottle if no fogging oil)
Make sure all fully drained of water, ensure any drain holes are not blocked. A couple of turns of the flywheel will make sure the water pump is drained.
Best stored upright ( over something to catch oil that will drip from exhaust) somewhere dry, slightly warm and airy.
Best not to store unused fuel ( except perhaps stabilised, non ethanol fuel in full, tightly closed metal cans.)
Renew pump impeller before next use if not done recently.
Clean and reset plugs before attempting to recommission.