My dental hygienist recommended that I use stim-u-dents as part of my regimen to fight my gum disease.
These are similar to toothpicks, except that they are flat. What you do is put one in between two teeth, up by your gumline, and then push it back and forth. This will not only get out any food that's left between your teeth that brushing may have missed, but it's also supposed to be good at getting rid of the plaque on the inside surfaces of your teeth.
I use them once a day, at night after I brush my teeth. I've also known people who carry a pack with them, and use one after each meal. They are packaged in something that looks like a matchbook, so it's easy to carry them around if you want.
They come in mint-flavored or unflavored. I like the mint. It's not a strong flavor -- just a little hint of mint.