Nothing irked me more than losing hand tools. I'd have that trowel in my hand one minute and the next minute it was gone.
replacing good tools got expensive. and frustrating. one afternoon while cleaning the basement I found a roll of weather proof bright red Christmas ribbon. aha! I tied a decent length to each tool and my spade. I have yet to misplace anything in the garden. the color hasn't faded and I can see it from a short distance. and it was free.