An easy festbier recipe:
50% pilsner malt, 5% Weyerman caramunich III, 5% Weyerman carared, 35% light munich malt, 3% acid malt, 2% Weyerman cara-aroma (added at mash out to reduce 'roasted' flavors). First-wort hop with 22 IBUs from noble hops-preferably Tettnang or Hallertau varieties. Single infusion mash at 152, boil 90 minutes, O.G. 1.054
pH is very important for this style of beer, both in the mash, and sparge water. You will want a residual alkalinity as close to 0 as possible, and this can be easily achieved with gypsum and calcium chloride. The high enzyme content from the pils malt will reduce the mash time. This combined with the lower pH in the mash will leech fewer tannins from the barley hulls. Cara-aroma contains no enzyme, so adding it at mash out will extract color and aroma while minimizing roasted notes that would be out of character. First-wort hopping will enhance the 'noble hop' character.
Decoction mashes can be fun if you want to brew old-school, but are generally unnecessary with modern malts, unless you have unusually low enzyme content in your mash. Heffeweizens can benefit from a single or double decoction because of the lower enzyme wheat malt as well as the high protein/glucan content that makes sparging an all-day event.