It’s really not that complicated- nothing you can do to you house will make more difference than what you put on the roof.* Save money in other areas if you have to, but use a wonderful material like wood, tile, slate or hand seamed and painted in place “tin” (actually “terne” and it’s made by Follansbee).
Here are multiple examples of simple houses that have wonderful roofs (borrowed from Content In A Cottage).
*presupposing that the proportions of your house are sublime, of course. No material of fancy detail can fix poor proportions.