One things this thread misses so far is dressing for a specific length of time in the saddle. For a one-mile trip to the grocery store, I'll wear anything that quick to don. For a 5-6 mile commute to work, I normally go for a windbreaking shell and a sweater or two and a base layer under the shell. For a 3-4 hour trip I might carry some extra clothes in a bag just in case I stop or break down.