Eating a variety of foods that contain potassium is the best way to get an adequate amount. 
Foods with high sources of potassium include kiwifruit, orange juice, potatoes, coconut, avocados, apricots, parsnips and turnips, although many other fruits, vegetables, legumes, and meats contain potassium.
Common foods very high in potassium:
* beans (white beans and others)
* dark leafy greens (spinach, Swiss chard, and others)
* baked potatoes
* dried fruit (apricots, peaches, prunes, raisins; figs and dates)
* baked squash
* yogurt
* fish (salmon)
* avocado
* nuts (pistachios, almonds, walnuts, etc.) 
* seeds (squash, pumpkin, sunflower)
Foods containing the highest concentration:
* dried herbs
* sun dried tomatoes
* cocoa solids 
* whey powder
* paprika
* yeast extract
* rice bran
* molasses
* dry roasted soybeans