Similar to Sandy Hutton's.
Take a piece of 1/4 inch round bar and drill 2 holes in the end at an angle so they come out at the side. You can grind a groove about 1/4 inch from the end and make the end ball shaped if you wish. Put a file handle on the other end. Feed the 2 ends of locking wire through the holes, hold the wire to the right length and twist with some tension and there you go.
This will get into lots of places that fancy wire twisters can't.
I've seen lots of people struggle in confined spaces with these over-rated tools and unless you are doing a lot of workshop or bench assembly I doubt you'll need them.
Also, a plea to all, PLEASE ALWAYS TURN THE END OF LOCKING WIRE BACK ON ITSELF TO STOP IT CAUSING INJURY. Too much blood has been spilled.
Hope this helps.