I find four-leaf clovers frequently, even when not explicitly looking. Many find this "gift" extraordinary, and even though this mutation is reported to only occur once in about 10,000 clovers, getting lucky isn't as hard as one would think.
Step 1: Background: the Clover
4-leaf clovers are a mutation of the usually 3-leafed White Clover plant, Trifolium repens. One clover is actually one leaf of a larger plant, with 3 leaflets. Mutations can occur due to a low frequency recessive gene or environmental causes. Often the reason for mutation is differentiable from one clover to another. The mutation does not stop at the 4-leafed variety: 5-leafed clovers are not uncommon. However, the more leaflets, the harder they are to find (and the luckier they are): the record is an 18-leaf clover, and the highest I've ever seen is 10-leafed.