I have my great grandmother's hand written recipes from the great depression and before. There are some amazing ideas in there about how to conserve sugar and flour in cooking and baking since they were on rations.
Sugar substitutes:
Honey instead of sugar: If a recipe calls for 1 cup sugar use 1 cup honey and remove 1/4 cup of liquid from the recipe.
Cactus Juice (read that as agave nectar): Peel cactus, press juice from meat of cactus and discard pith (assuming this means any solids) use in the same ratio as honey. Only pick as much as you can use it doesn't keep (this may not be true today with modern refrigeration).
Flour substitute:
Non flour thickening agent: Shred potatoes and dry in the oven (use a dehydrator if you have one). Store for future use.
Thicken gravy: Grind dried, shredded potatoes to make powder. Add half potato powder and half flour to your gravy.
For breads: Use potato powder on your counter instead of flour. Use 1/4 potato powder in place of flour within the recipe.
For cakes: Line pan with butter and a 1/2 and 1/2 mix of flour and potato powder to prevent sticking to pan.
My favorite tip out of her book: "Dry mulberry leaves for tea, save the berries for wine no matter what Annabelle says." Annabelle is my grandmother who to this day loves mulberry jelly.
That is such a great gift to still have her recipes - have you placed them in laminating paper? If not do so. I have a number of recipes from my family - and placing clear laminating plastic over them keeps them forever.