There two school of thought here, like was mentioned weather the storm with postion and strong hands or chip up early with a double up. Shoving early you take a chance with possible getting a few callers. Later into the tournament you might get HU with a strong hand. Playing multi-way pots early can leave you wishing you would have folded.

I prefer to sit back and let the gamblers gamble, then play the poker players in the game we know and save myself from turning in my bingo card early.