Yeah I've done it like 5 times over the past year, luckily for me when meeting new people/ people I haven't seen in a while I don't stutter much and when it comes to actually approaching the girl, the strong sense of attraction completely halts my stuttering (this happened twice). If you want to work your way up to it, become a more social person in general, from talking to shop assistants, to talking more with your friends and talking more with strangers. If your counting the times I havent' been successful it's never been due to my stutter, sometimes she isn't interested and I cba to push for a phone number, mainly because there are tonnes of other girls out there. My best advice is it comes down to general social and charisma, on top of confidence, if I'm not feeling confident I DO NOT approach a girl, but when I am I'd probably do a couple a week sometimes I just stop for a chat (like in a coffee shop) but don't ask for a number because I'm not that interested or she might look different up close