Listen to ATC and build up a picture of where other traffic is in relation to you and whether it will be a factor, especially in the circuit, there have been a lot of mid-airs over the years in circuit patterns and at least one aircraft landing on top of another (Cranfield late '80's?) where one pilot strictly followed procedures and found another aircraft just where they didn't expect it.
And having re-read SNS3's post, there is an awful lot of good advice in there. I would add, fly defensively, expect the weather to be wrong and have a back up, expect someone to burst his tyres on the runway you are going to and have another in your plan, expect everyone else to not be thinking as you do so allow for them making the mistakes that your awareness will stop you from making.
SND