Now that the palyers have a history and have chosen the type of class they want (fighter, magic-user, cleric, thief) often with discussion amongst the group, it comes to the dreaded "roll of the dice".
This is an important time for the DM to understand something. It is not about pitting the players against the dice - it is getting something reasonable within the rules that the player can use to develop his character. It should not detract from the fun of the game but add to it.
To that, my group employs many different character ability score techniques. I usually let my players decide how they want to create them. Here are just a few:
(1) 6x 4d6 picking best 3 die
(2) 7x 3d6 then choose the 6 they wish to keep (most often chosen method)
(3) 6x 2d6+6 (choose again)
(4) 6x 3d6 re-roll all ones
(5) some base score (like 9) and some base numer of points + some value rolled. Points can be spent then on increasing the ability scores - points can be removed from the base score to be used as well.
The player can organize the scores however they wish. If a player has two or more scores with penalties, they must keep one score but may re-roll the other(s) if they wish to do so.
Different players choose different methods each time but I'll tell you, whatever anyone is doing, they stop to watch (and cheer or bemoan the players luck).
I find that using these methods adds fun and excitement to the character building process and by allowing the player to choose, they can build and identify with the character they create. It generally allows them to be what class they want (or if not, the DM could intervene - it is all about fun after all!).
have a good weekend!