Check your face: Seems basic, but you've seen the pictures with food in teeth and crumbs in beards. Don't be them. Check yourself, before you embarrass yourself.
Location. Location. Location: If you don't want your picture to end up online in the selfie hall of shame you might want to insure your surroundings are up to par. Hide any unmentionables that might be laying around and be aware of any questionable bystander activity. Otherwise, a selfie can be taken anywhere; almost. Good judgement goes a long way.
Filter: Now that you've selected the picture you'd like to share add filters and effects that fit your mood -or don't and add the ever so popular #nofilter
Caption: Since pictures do say a thousand words, there is no need to a hundred of them to your caption. However, a short phrase with the right hashtag could go a long way. Don't try too hard though. Be yourself.