It's TRICKY isn't it!? I'm on my 2nd pair, the first came out so big they're too big for my hubhub. (dh) But he loves them anyway... I'm going to felt them down a little.
Some sock patterns, like in the sock book I have actually state how long the toe part will be. One of mine says 'will add 1 3/4 inches". I like that.
I'll be glad when I've made several pair so I can begin to do exactly what my foot is. Custom - made - socks!