I use a pistol lanyard (rubberized coil) to connect my compass/slate combo, brass clips (dual ended) to keep my alternate close to my body and if I wear gauges brass clips to keep them close to my body (I have a hoseless wrist computer gauges are my back up for big trips) the brass clips attach to my D-Rings. I use the lanyard from my flashlights through the D-Ring and then the flash light through the lanyard to keep them attached.
When I wear a knife/cutting tool (Seat Belt cutter) it is attached with a hook and loop (velcro) strap. I have a small third back up light attached to my shoulder strap with a hook and loop strap.