I will generally change gears as I spend more and more time at a table. If I have been raising only good cards, I will start to slowly work in different (weaker cards) into the mix. After a while I will start raising hands I wouldn't and limping or min raising strong hands. Alot of how I play depends on the play I get back at me. If I'm at a super tight table I will start to raise more and more hands, knowing if I get a call and big cards come I'm WAY behind. If the table is looser I will start to limp/min raise stronger cards knowing I should get a raise behind me. This will allow me to reraise and isolate the raiser.

I don't have a specific period in a tournament where I change gears, rather it depends on the dynamics of the table.