I've never had a good run with rejecting people... I've never broken up with a girl... I've always just changed until they didn't like me anymore and broke up with me... I find it even more difficult to turn someone down if they're just flirting...

Today on my way home from school I pretty much got stranded and had to walk with this girl... I'd seen her around but we'd never really talked... Reasonably attractive but doesn't really do it for me... For the whole hour or so of us walking she was dropping hints and using kino on me... It was almost over the top... Most of my replies to her flirting were just me saying 'yeah haha'... I didn't respond to her touches but I find it difficult not to because it just feels like I'm giving her the cold shoulder...

What should I do to be polite but show that I'm not interested... I don't want some formal conversation where I turn her down... I just want to make it clear through body language or interaction that I'm not interested...