Buck knife with leather sheath ( Any brand of knife with a sheath will do)
Leatherman Multi-Tool with sheath (Again any brand of Multi-Tool will work)
Waxed thread with heavy duty needle
Take your knife sheath and multi-tool sheath. Place the multi-tool sheath on top of the knife sheath. Make sure that the sides match or are very close. Clamp these together. I had to use a drill as the leather on both were so thick. Mark holes on both sides of the multi-tool sheath and drill through both sheaths. Once these are lined up, put a small amount of contact glue on the back side of the multi-tool sheath and clamp it to the knife sheath with the holes lined up.
Now take a good length of heavy waxed thread and thread it through your needle. Stitch the two together running the thread through the holes that you drilled. Start underneath the knife sheath and tie a good knot at the end of your thread. Run the thread through the holes until you reach the bottom hole and tie a sturdy knot. Repeat this procedure on the other side. The thread I used was tan in color, so I just used a black felt marker to blacken the thread.
You now have a great knife-tool combination. Both are easy to access. If you have an questions, don't hesitate to ask