Maybe pan-handling works for some, but speaking from my own experiance of sitting outside a train-station holding a card that said "Homeless & Hungry, Please spare some change, God bless you!" from 8 O'Clock until 3:30 in the afternoon was the most unproductive way I've ever spent a day, not a single person spared so much as a single penny!
As for scavenge for food, I think you mean a similar situation I witnessed once when a lady wondered into the midst of our little gathering and offered to sell us all a roll... To which I fired up with, "no thank's, we're all homeless!" and she fired back "yeah, I figured as much, but thought you must have 99 pence from begging!" dude, the conversation amongst the crew dropped within a heartbeat, suddenly she had all three of us around her going "is that the chicken an mayo, is that one the corn beef hash oh and thats the egg and cress right?" whilst we helped ourselves and looked like we where fishing for change, then with one quick nod, we all legged it in differant directions! LMAO!
In the UK only the Junkies scrounge for spare change, just so they can get a fix!
If you where going to make a shelter, I would have some suggestions, like a fold up plastic card house that could be erected quickly, but saddly in my own country the UK if you erect any temporary shelter, the local council's can have you detained and fined for doing it! Not to mention if you dont erect it off the beaten path, people would probably presume it was a rubbish recepticle and chuck there crap in it!