I'm useless at fibbing: bad memory for one thing, and I can't control my facial expressions very well. So I stick with evasions or silence.
For instance, if a friend asks if I like her new skirt/hairdo/outfit, and I really hate it, I avoid the issue by saying it's no good asking me 'cos I'm useless at fashion (which I am).
For most things, I just have to be honest and take the consequences. No choice really. People put it down to my Yorkshire outspokenness, sometimes.