Use two washers of the proper size to set the upper and lower parts of a grommet in a fabric hole. Put one washer on a solid surface - a block of wood or a brick will do - and centre the eyelet (the lower part of the grommet) on it. Push the eyelet through the hole and fit it to the upper half of the grommet. Position the other washer on top of the upper half and hammer it down.
A sewing-machine buttonholer will reinforce a fabric hole, though not as securely as a grommet does.
For temporary reinforcement, try sticking small strips of tape around the edges of a hole in fabric.
You can recycle grommets from old plimsolls. Cut them off, then open them up with needle-nose pliers. Slip the grommet into the hole in the new fabric and then close it with a hammer.
