Cut vegetables into 1/4" thick slices. Make diagonal cuts on shrimp to help straighten.
In a bowl, mix all the flour (rice flour, potato starch, tapioca flour), baking powder, and salt. Add ice water and whisk well.
Heat oil to very high temperature (180C or 375F). Dip vegetables and shrimp in batter, and deep fry until they float and are cooked through.
Serve with Tempura Sauce or salt.