One of the most imprtant things about improv is that you listen to the improvisers that you do a scene with. Mainly, so you realise what is happening in the scene and also so you can develop on what has been said. Listening to the person in front of you on stage is sometimes more important then thinking about what you are going to say next.
There are many reasons why this is more important – the first is because you need their words to develop the situation as to what is happening. Some of the most important snippets of information can be made by your scene partner and it is so important to pick up on to create a strong scene.
Also, there is anotehr problem is you are on stage, focussing on what you are going to say next – what you are planning in that moment may not go with what your scene partner is about to say and that is why you need to pay attention to them – to make sure what you say next is coherent.
Planning what you say can also lead to you getting too much insde your head which can also effect your scenework because you can really start judging yourself too harshly in the moment.
So the next time you are in a scene – make sur your partner is your focus!