I use a fly machine which simulates a hugging motion. As far as I know, the chest muscles can only do two things: press and hug. So I do at least one exercise to cover each of these actions. Seems to work pretty well...
bigguns15
When you say it varies by 10%...Do you mean the difference between 10% BF and 20% BF or the difference between 10% BF and 11% BF? I could live with the latter in terms of accuracy...