I'm sorry about the sarky remark but I couldn't resist. The thing is everyone's experiences, expectations and needs are different so one man's sex goddess could be another man's unmoving plank. If you genuinely feel there is something wrong or needs improvement you should talk to your partner, or if that's not the problem then talk to your friends or invest in a bunch of glossy magazines (Cosmopolitan has made a career out of sex) or perhaps you could wonder along to amazon.co.uk, Tracy Cox does a nice line in helpful books.