Sock makers, how do you....

[feministmama]

reinforce the heel? My socks just don't seem to last long (which is why I knit so many) but I want them to last longer. I usually use 100% wool, sometimes worsted wieght and I wear them just in the house as lounging around socks, not in shoes. It happens with 100% wool sock yarns too. I've heard some people say stranding a piece of nylon in when you do the socks but that sounds uncomfrotable.

So lets hear your ideas sock knitters!