First, a side note. The last tip (and most of these tips) do not apply if have your house number painted very clearly on the curb in front of your house, have a mailbox by the curb with your house number in clearly visible (which means non-reflective) numbers on both sides (and the "door" of the mailbox, while you're at it), or both. These homes are very easy to find, and are a joy to delivery drivers throughout the world.
Now, the tip: Who cares if they don't look pretty; the bigger the numbers, the better--especially if you're not close to the street. Ain't tryin' to read inch-high numbers on a house half a football field away from me!