The first thing that most people do every off season just prior to the opening of a new fancy goose hunting season is to head to the local sporting goods store (or as time goes on, the internet and web based stores) and go out and buy a new set of goose decoys and if their heart so desires one of the many fancy new goose calls on the market today. This can be exactly what the doctor ordered if you don't have many decoys, the ones you have have seen better days, you blow your goose call like a man strangling a goose, or a similar malady. However, if you don't have these afflictions (and truth be told the majority of us don't), then you would be better served spending your time and hard earned money elsewhere.
So where would that be you ask? Scouting and concealment. Take time to scout out areas where geese are feeding and continue to feed all year long. Seek permission to hunt the areas that are private and take time to fine tune the best spots on public lands and how to get to them effectively. Don't be the guy who just shows up 30 minutes before shooting time thinking he can somehow make his year get off on a good foot with no leg work.
The other key thing to consider is concealment. Have a way to hide yourself from the prying eyes of passing waterfowl. Make it a point to blend in as best you can. If you need to purchase blind making materials or a sweet layout blind, then make that happen. Perhaps it is your hunting attire that needs updating. If so, find one of the many new school patterns that match just about any type of cover hunters face while out in the field.