First thing is to reduce monthly cash outlay, pay off the debts as much as possible before retiring.
On a fixed income the things that are needed such as electricity is a good place to start. LED bulbs cost way less to use, the cash outlay for the bulbs if done prior to retirement is a good investment. LEDs last ten times what a typical screw in flourescent bulb does, uses 10% of what they use in power. That savings though not much will help over time and definately when your on a fixed income.
Home heating and air conditioning, insulate now and start saving right away, upgrade your doors and windows. Having a good home heating and airconditioning tech check out your system and point out your needs can save as much as 40% on your annual costs, many homes have a too large of a furnace pushing too much CFM and causing a heat loss through inefficient transfer to your ducting. Too much causes this, too little causes furnace overrun. Tankless water heaters are a good saver also. Upgrading your clothes dryer to a newer more efficient one can save you more when on a fixed income.
Vehicles, one good compact SUV can help when retired in gas savings alone, smaller luxury vehicle ditto.
Insurance company needs to be notified of your retirement, less time on the road means less chances of accidents.
Simple things like cutting the grass, using a push mower helps you stay fit costs less to operate than a rider (get the wife one too)
Victory gardens, if you have floral gardens it don't hurt to put a few pepper plants, tomatoes, ect in with them seeing your taking care of them anyway. Growing edible greens, herbs and seasoning all helps.
Having a good freezer for storing fish fillets (you caught) wild game ditto, and frozen veggies from the victory garden.
During the winter it helps to have good warm clothing for indoors to conserve heat, I set my stat at 68 degrees and I'm comfy.
Planning trips to conserve gas is a good thing to get used too (The shopping list is important here) put every need on it and try to pick up all on the list. Stocking up on staples especially when on sale, things like TP, cleaning supplies, shampoos ect. If you do your own oil changes, having a large amount of stock will help over time.
Most often old timers get 100% free checking and that includes on line banking for paying the monthly bills and others say like a quarterly trash service, home heating bills it all saves in stamps ect.
The single most expensive grocery item I buy is when grand children are visiting, make your kids and grand kids understand if they must have something special bring it along, your retirement dollars don't stretch. Having a cookout sure you'll spend more but then you have to splurge once in a while, but having a buckburger and free range chickens on your property don't hurt none.
Making a half of pot of coffee instead of a whole one if your not going to drink it all saves a quite a bit over a years time.
Drinking water instead of soft drinks makes more sense, if your tap water is hard consider buying a filter vs buying bottled.