Usually the first trick is the most important. Each half turn increasing the spin score that will be used on the first trick. The final spin value is initiated into the trick score as soon as the skater safely lands. This does not affect or prevent the outcome of other influences acting on the individual or chained tricks. No matter how much or little spinning you do during a trick, the multiplier treats it as one whole trick.
Lets choose a fair point valued move.
A trick named Kickflip is worth 100 points. While high in the air, usually done with aid of a halfpipe, you begin a 180 spin. Now the first spin value is in place. The spinning increases to a 360. So far, nothing is done to the kickflip score as the spinning reaches to a 540.