Despite the annual cycle of vintages and stately chateaux that project an air of calm permanence, the world of wine is really a tumultuous place. As in any other industry, fashions and trends drive sales; regions fall in and out of favor; varieties are darlings one moment, duds the next. No wonder consumers find the process of buying wine mystifying, and a bit overwhelming - especially at the holidays. If you’re eager to fill out some wine lover’s stocking with a special bottle this year, we suggest cutting out the tumult by focusing on guidelines rather than specifics.