I'm no expert, but when it comes to walls, I think the old adage "less is more" can go jump! I say the more the merrier and the bigger the better. Perhaps it's a passing trend, could be personal preference, but sadly, walls are an area so often a neglected by the average do-it-yourself-er. So whether its mirrors that float your boat, wallpaper that blows you hair back or vintage plates that butter your biscuit, just go for it. And don't go feeling bad about drilling holes in walls - That's what they're there for!