Which procedure is the best way to find the correct mass of an object in a laboratory experiment?

1)make sure the balance works correctly before starting the measurement. Record the mass for three trials. Then average the masses.
2)Readjust the balance after getting the mass and repeat.
3)Have two classmates use different balances to determine the mass of the object. Then average the masses they get.
4)Determine the mass of the object using one balance. Then measure the mass again using a different balance.

I think it's either 1 or 2 but i'm not sure.. Please help me!!!