When I was a kid many, many moons ago I used to love the start of Autumn so I could go climbing trees to get conkers. Graveyards used to always be a good source of trees too and so we'd spend hours shaking branches and trying to get them to fall so we could build up a canny collection for the school yard games.
There were allsorts of 'methods' to try and harden your conkers. Baking them in the oven and covering them with clear varnish were the two main ones, though others used to swear by soaking them in vinegar for a couple of days etc.
Most kids these days haven't a clue about conkers, schools used to cite health and safety as a means of spoiling the enjoyment. However, my kids have always gone to get conkers and every year we go get some and its great to spend a couple of hours out in the fresh air looking under piles of leaves to see if we can find any. No climbing of trees these days though, I fear no branch would be strong enough to hold me on the off chance I could shin my way further than 6 inches up the tree