In general, most programs don't have any way to spend small amounts of miles.

A few of the very biggest programs (AA, UA) have multiple ways, and a few more may have magazines only.

But with most programs, the only use is once you have enough miles for a short flight with a partner (inter-island in Hawaii or short hop in Europe, for example). But, of course, that only works if you happen to get to wherever that free flight can be taken (it's useless if you want to spend the miles without traveling to that specific destination).