Buy feed, shavings, and hay in BULK.
Label everything so that other people don't use your stuff thus buying less.
The finer the shavings the less you use and it takes less time to clean.
Depending on the area, you can substitute rice hulls or go half and half for bedding.
I use a fish net to sift dirty water buckets.. I won't dump water buckets or troughs unless they are low or really dirty. Saves time and money and less mud.
I try to buy most of my tack and riding clothes on ebay
When you go to shows.. sign up with the feed dealers like purina. Fill out multiple cards (1 for you, 1 for your husband, sister or what have you.) They send out $10 feed coupons all the time and when they do I usually get like 4. $40 of feed every month or so is really nice!