When I brush my teeth I also gently brush my gums, and if it doesn’t gag me too badly, I quickly run my toothbrush across my tongue. You should brush your whole mouth – it cleans out “gunk” and stimulates blood flow. And @chyna‘s right – a soft brush is what dentists recommend.
If I’m out, I go to the bathroom and put warm water in my mouth and swish it around and spit it out. If I’m home, I do the same and then I brush my teeth.