I get approached by people who I don't mind approaching me, for the most part, so I'm happy with that.
People trying to get signatures in the street or preach their cause tend to get blanked by me so I don't have the problem of the constant Princest Street brigade going "Talk to me instead of doing what you intend on doing c'moooooon!" to me. I don't look at them, I look past them. And then walk where I'm looking. They tend to just go for some other person, and yay for that. Danielle has it opposite, she's impossible for them to avoid unless they're with me. That's probably just 'cause she's hot, though. But yeah, it's annoying to have to constantly tell people that I'm not going to help their charity because I'm already helping other charities and to be blunt, don't want to give away any more money right now.
I get approached all the time for directions, though, and if I can help I'm more than happy to. Likewise if people are just a little confused about buses or whatever, I'll happily help. I don't mind talking to people when they aren't trying to get money out of me, basically.
Sometimes a drunk will come up to me (this is not terribly unusual in Scotland, of course) and talk about some nonsense and I'm okay with talking to them for a little. I tend to half wish they would go away so I can stop being bothered, but the other half amused at drunk talk. So it's no big deal.
And finally there are the 'unavoidables'. People going around asking for that bit of money to get a bus, make a phonecall, whatever... always looking like junkies, oddly. What a shocker. Anyway, I just say "No, I only use card" (which is actually the truth) and they move on.