In a full stacked 6max cash game, I generally raise pot in position and add a bb or two OOP.

My understanding with tournaments was like this:

blinds 50/100

EP raises to 300

You find AK on the button, you reraise to 900.

Now it can depend, on stack sizes, your opponent, position, etc. Some players might just call a raise with position rather than potentially committing themselves preflop with AK, KK, QQ, etc., because they feel they can outplay their opponent post-flop and/or get away from a hand if needs be.

But typically I'm reraising 3x the initial raise (or pushing if my stack size makes a 3x raise a pot-committing raise)

Some players might also do the stop n' go where you smooth-call out of position (i.e. the blinds) and then push any flop. Since your stack size might not be large enough to push someone with an all-in move before the flop, you might have a shot after the flop comes if they miss.

An example would be this:

You hold AQ suited in the BB. MP player with pocket 8's raises from 100 to 300. You only have 1,000 chips left. You smooth-call and the flop is 5JK. You have missed, but make the push. He may fold now that he's seen two overcards to his pair, while he likely would've called your all-in if you pushed preflop.