Well, you can load yourself up on a bunch of GOD/Luck, or you could just ignore it. Luck only enhances your chances for a critical hit, but you knew that right? It doesn't affect your rate of finding cool stuff or anything like that
Luck mats and slot peices. As already said though, don't worry about luck that much. The reason it's rare to find so many luck materials is because it's not worth that much and it's a waste to use that when you could use a different and more important kind of material.