You can't be a predictable in a no limit tournament. One of the keys to winning tournaments is to be unpredictable. The easiest thing for your opponents to notice is the size of your raise as it relates to the relative strength of your hand.
Here are some typical examples:
a) An Ax hand: "I want to risk a small amount, it's not a great hand. I'll put in a min-raise."
b) A Premium hand. "I'm suppose to raise three or four times the big blind."
c) Pocket Jacks. "Not freaking Jacks, again! I have to protect this lousy hand and raise six times the big blind."
d) Pocket Aces after another player has raised. "I want to get more money in the pot without chasing away the raiser. I'll set a trap and just double his raise."
If you decide how much to raise based solely on the strength of your starting hand, you are making a mistake. You need to vary your game, and keep your opponents guessing. You win the most chips when your opponents make mistakes.
Therefore, before you raise consider your position, opponents, stack size, the players in the blind, etc. If you still end up getting into a habit of sizing your raises based solely on the strength of your hand, use something totally random to help you.
Some players have been known to use the second hand of their watch. If the second hand is between 0-15, they raise two times the big blind, if the second hand is between 16-30; they raise three times the big blind, etc.
But don't go that route.
Instead, if you are unsure how to keep your opponents guessing, don't vary your raises at all. Always raise the same multiple of the big blind regardless of your cards. You won't have to worry about giving away information about the strength of your hand. Just make sure to increase the size of that raise when the antes enter the game.