I always re-use plastic bowls from frozen foods or butter dishes.

I sold Tupperware over 40 years ago and I am still using it! They have wonderful products for lunch boxes and snacks. When I got married and had children, I used them and now I am using them for grandchildren!

I purchased 2 sets of glass containers with lids for using in oven, refrigerator, freezer. I've made dishcloths from textured towel. Purchased refillable metal spray containers for mixing organic soap with water, and pine oil soap with water for heavier uses. Cloth rags not paper towels, sterilize with vinegar & baking soda in separate wash. Sewed own "sponges" with heavy textured cotton fabric from worn dress. Sewed extra electric mop cover using old textured rug, the original cover as the pattern. Vitamin jars use for storing spices, keep toothbrush in water/organic dishsoap mixture in bath cabinet.

I prefer cotton underpants--which are, by definition, highly absorbent. When they wear out, I dispose of the crotch and elastic, and just use the body for cleaning over and over. (After all, cotton washes...) These things are soft, absorbent, and we've used them for years and years past their 'human use' lifespan. (Learned this one from my mother.)

I use old towels and tee shirts for almost all my dusting and cleaning. Kitchen counters, floors, etc. They look so much better when you dry them immediately after cleaning. Also drying dishes, especially big pots and pans.
I also use old clothing for quilting. I’ve made 3 denim quilts from all the not quite wearable jeans.