Do girls like random guys approaching them? Watch
also depends(not to be shallow) but if your below average you'll come across as creepy especially if you stutter. but if your hot it could work.
The best option instead of asking them directly for their number or snapchat also, is to offer them yours. Then it puts them in the position of power and means they aren't creeped out as much or feel pressured by you/harrassed.