Metallics have been on the rise for some time now and are quite simple in application but don't go overboard. A little goes a long way.
The brand I like most is Modern Masters but you can find many alternatives at both Home Depot or Lowes. Keep in mind that depending on your application some are opaque while others are semi-translucent and will not cover your surface. In all cases it's imperative to apply an undercoat within the same color range as your intended finish.
One of my favorites is copper metallics with a eggplant glazing. If you've some texture on your walls the glazing will adhere giving depth and the metallic a nice richness. There are special rollers for metallics to help avoid lap lines but a nice and easy alternative is while rolling on your finish just use a dry brush to soften those lap lines. Simply take the 4" dry brush and lightly go against the direction of your lap line, also make some additional random brush strokes throughout your wall to even out the pattern. Often I've used a circular brush called a "neon" to make soft circles in my finishes which reveal a beautiful pattern.
Tools: metallic paint, 4" brush, 9" roller, glazing compound.
Have fun! Vaughn