Winterizing - freeze protection
Many of us use our boats occassionally throughout the cold season, so we "winterize" often. I'm no expert, but I know of three key steps.
1. You've done this already, add a good stabilizer to any fuel left in the boat.
2. Make sure all cooling water is drained from your engine. When I pull out of the water, I always lower the engine and let any water in the cooling circuit drain. Complete draining in lower temps is critical. Be sure to remember to raise your prop before moving the boat.
3. Flush a non toxic antifreeze thru your live well circuit(s). You can buy propylene glycol based RV or boat grade antifreeze.
I'm sure your boat shop has a few additional items on their list. But I suspect most of those are more routine maintenance related. From what I know these three are really the critical steps to prevent serious freeze problems on most fishing boats.