When one glove in a set goes bad, I use the remaining good glove in combination with other remaining good gloves. The bad gloves eventually get repaired or thrown away. This instructable shows the way I repair them.
Step 1: CLEAN THE AREA
Step 2: CUT THE PATCH
Remember to clean the patch with sandpaper also where the glue needs to stick.
Step 3: SELECT YOUR GLUE
I have tried contact cement, rubber cement, epoxy, and silicone without great success. This stuff sticks well, is waterproof, and has some flexibility, but nothing is perfect. This glue foams up some, expanding when it hardens.
If the hole to be repaired is in an area of the glove that is used for spreading cement (edge of the palm), you might want to cover the patch with a piece of wax paper and hold it in place while the glue expands and hardens. That way the glue will harden up flat. The wax paper can later be removed.
Step 4: APPLY THE GLUE
Small pin holes need no patch, just a dab of glue over them.
To put on a finger tip patch cut from another glove (kind of like a condom), it helps to fill the finger of the glove to be repaired with something to keep it inflated. In the picture below, I used a small plastic container that fit inside the finger nicely. The end of a broom stick might work, or something else finger-shaped. With the finger stuffing in place, the patch will fit better until the glue hardens.
Let the glue set and you are done.