Pouring directly into glass; over carbonated; warm beer is being poured into a chilled glass - all assuming you're pouring from a bottle and not a keg.
Pouring from a keg. Clean glass. Did use a heading agent [Muntons Kreamyx] - would it be better to leave this out next time or does it add an extra level of flavour?
Is it to the exclusion of actual beer, so that it becomes tedious to get a nice glassful? I must ask - did you try pouring down the side of the glass? I apologize if you already tried this.