For a richer custard, use whole milk. You can also substitute half-and-half or cream for part of the milk. Be careful not to overbake the meringue, as it can become tough and weep. For a more intense vanilla flavor, use vanilla bean paste instead of vanilla extract. If you don't have time to make a graham cracker crust, you can use a store-bought one. Make sure the bowl and beaters are clean and grease-free when beating the egg whites for the meringue. This will help the whites whip up to stiff peaks.