Normally I do the following, 4D6, keep the highest number. I try to do it order as much as possible, Strength first, etc. If I'm trying to create a specific class of character that has a minimum, when I get to that number if I don't roll something extraordinary, or if I roll say a 8 and the minimum is 9, I usually bump it up to the minimum. On occasion I will subtract from another stat to make that work.
What's your method?
The reason I'm posting this was that I grabbed the basic fantasy rules the other day to roll up a character that was 3rd level, and it took me seriously like 10 mins, love that about OSR stuff.