It turns out I'm quite an escape artist, too. It's almost impossible to tie my wrists together without me getting loose. Adding elbow bondage definitely increases the effectiveness (assuming sufficient flexibility). When it comes to leather cuffs, the three important factors are thickness of the leather (so it can't stretch), snugness of fit, and an effective lock. Any method of tying the wrists apart, rather than together, increases the security of your bondage.