I've been fortunate to have a handy husband, who picks up things that he knows I might have a use for.
One thing that has come in very handy, due to my intense dislike of weeding, is old carpet.
With many homeowners going with new flooring of hardwood, or the versatile and low maintenance option of laminate flooring, out goes the wall to wall carpet.
I cut it into strips with a razor knife, aiming for about 2' (60cm) strips.
These are the perfect width for pathways between raised beds or even for my nursery where I grow lots of hardy succulents.
For smothering the weeds under the hay bale garden I'll cut a piece that's more square and build the hay bale garden in a circle so I can reach every bale - much easier to water it too.
The weeds and even the roots of the cottonwood trees can't get through. I move the strips of carpet around to disturb any seedlings that might get started, and that is enough to eliminate them over time.
The best kind of old carpeting to get for this purpose is with the woven jute backing. I like berber style rug, and even that with the sponge foam on it; as long as it keeps the light out, it will work.
After several years, the carpet will start to disintegrate, and then it's time to go to the landfill. Unless it's completely natural fibres, it will never rot down, but you'll be picking out the little tufts of pile for a long time if you don't get rid of it.
At least it got one more use, so don't feel too guilty if it's got to go.