For something small (around a foot), you could probably get away with a little bunny hop (compress the suspension and explosively shoot up). Just be sure not to get overzealous or the bike may land awkwardly (one tire will go up much higher than the other).

The other option is a pedal kick. If you can wheelie, it's similar. I use it to get over high curbs or logs where you need a little umph that lifting the handlebars alone won't provide. I'm sure something posted above covers it, but basically you want to shift your weight back, and when your foot hits about 1:00, you want to quickly snap it, popping the front end up. Practice on the grass before moving your newfound mad skills to a drop. This will be a really handy skill for the trail and a way to get over most obstacles.