FAQ says:

How is the speed of a coin calculated?
Every transaction has a time when it was first seen in the network (timereceived) and a time when it was included in a block (blocktime). The difference between those two timestamps is calculated as a laziness factor. The higher it is (the more time a payment needed to be included in a block) the slower is the coin. The least lazy coin in a race wins the biggest part of the pot.

To get a fast coin, you can try to predict when the next block will occur and make your transaction shortly before to get it confirmed in that block.