Here is a handy hint when pre-drilling to a specific depth.

Place a piece of tape around the drill bit at the desired depth you wish to drill a hole.   This tape will act as a visual guide when drilling.

If you are anything like myself, when working in the garden I am constantly putting my tools down, and then forgetting where I had last placed them.   So to solve this problem, i have painted my garden tools bright red.  this makes them easier to see against soil coloured background.    However, in hind sight I should of painted these a bright pink, that way they are more likely not to be claimed by others.

Visit your local hardware or paint store and ask for an epoxy enamel paint.   This is preferred, as it will dry hard and is suitable for the wear and tear that your tools will be exposed to.   You will need no more than 500 mil, to give your tools a couple coats.   Your tools will come up as good as new.     This is also, as great tip to give life back to any old tools that you may inherit or find at second hand trash and treasure markets.