When building a deck, always nail a thinner member to a thicker member. Hot-dipped zinc-coated nails are a good choice. For more holding power, consider using either ring- or spiral-shanked nails, or go with deck screws. If using screws, it's best to pre-drill pilot holes.
To make a room appear taller, paint the ceiling the same color as the walls. This eliminates any break between the two and gives the illusion of height.