We don't usually have beggars where I lived, but we do have buskers and people selling the big issue. I ocaisonally buy the big issue, and I'll always throw some change to a busker, it takes some courage to perform in public, there was a lady singing opera one time that was awesome.
I'd only give money to beggar if they came up and asked and only if they're brief and honest (well not straight up lying) in their proposition, this one time a guy gave me and my friends a long winded and ludicous story about how his brother was going to beat him up for 30 dollars, it was so bullshit and the guy was obviously a drug adict, he hurled abuse once we started walking away. But once I was actually asked by a guy if I could give him money for a pot of beer, I was like I shouldn't be doing this in my head, but hey he was honest.
When I'm out at night, I usually carry a large pile of coins in my hand in a pocket of my jacket. It's more a self defense thing, if someone tries to jump me or my mates, I'll throw them at them (it's surprisingly distracting, the first impulse is to shield yourself). But a secondary advantage is I usually have some coins for buskers and beggars.