I depends on what level you are playing.
To be honest, playing low level buy in MTT`s, you would be better just keeping to a TAG style because
1) Most people at the table are not paying attention to you.
2) They don`t play pot odds
3) Some will push with any ace, regardless of action.
4) Any 2 cards of the same suit are worth a go...
and so on.
If you feel people are watching you, rather than change your image, us it.
So, if for example you have a TAG image, try raising from middle/ late position with less than big holdings (e.g. I will sometimes raise 3 - 4 times the big bling from middle position with say A8s if there have been a few limpers before me.
There is no right or wrong way to change gears. The main issue is if u do as I sugest and raise with say A8s and then u r reraise big, u must be able to fold for 2 reasons, being 1) u r probably way behind 2) you don`t want people to see what u r trying.
But, in essence, there is nothing that beats experience.