changing gears in tournaments?

[stackenvy]

I been playing for about 3 years now,but still consider myself a beginner to the game.And this happens alot to me in tournaments and in cash games also,I'll often myself trying to change up my play in what I believe are good times to do so.But I also seem to get alot of people catching onto my play,and calling me down with bottom pair/weak kicker.Am I not doing a good job of being deceptive,or more expereinced-seasoned players see this more often than not and can spot it from a mile away.Is there something I am missing here or what.I play in B&M casinos mainly so do i need better acting lessons or something?