I assume you're using the "good stuff" that's unflavored, which is what I use a ton off.
I add in a sweetener, either stevia or sucralose. For flavor, I'll add vanilla extract, cinnamon and dash of nutmeg. For post workout drink, I'll decrease amount of protein, and without those added sweetners and flavorings, add 1 cup of frozen blueberries or strawberries or a mix of both (when I begin to run out of one) and 50g dextrose.
Sometimes, for non post-workout drinks I'll also add "some fruit" in. A favorite is unsweetened applsause and natural peanutbutter!