Sorbets and granitas are lighter and often less work than ice cream. Judy Rodgers of the Zuni Cafe gives great instructions for granitas in this recipe for Espresso Granita - just chop the frozen mixture with two pastry scrapers.
Sorbets, with their finer texture, are better made in an ice cream maker. Here's a tip we learned to keep them fine-grained......freeze them for a much shorter time in the ice cream maker than you usually would for regular ice cream. We usually run our sorbets through for about 15 minutes, then freeze them until firm. We also usually include a measure of alcohol in our sorbets, to keep them from freezing too rock hard.