You need to think in advance about ways to break the ice with people, it also depends on the situation.
If you're at work, in a shop or on the bus or something and your interested in getting their number/talking to them then you need to do/say something that they will remember tell a bad joke and apologise and laugh about it being so bad. Ask an odd question that they won't be expecting like if you had to choose, what would you say is your favourite type of dinosaur? It seems strange and it will put some people off you but the way I see it is that I'm a person with a sense of humour and would like to spend my time talking to people who also have a good sense of humour. If talk to a girl and it turns out she takes herself mega seriously and is just looking for a trophy pull for the night then (tbh, depends how attractive she is yano...) I'm not really interested. I was donating blood the other day and while I was sitting waiting an attractive blonde woman who looked a little older than me asked me to stand so she could get past to sit down. When she sat next to me I said hi (literally just "HI") and was going to mention how damn hot it was in there, he instant reaction was to, without even looking up from the magazine she was holding, raise her left hand to show an engagement ring and said "I'm engaged" and continued reading. Rude ass mother Fer. You will sometimes get reactions like that, in that case just drop it yano?
Tailoring your language/approach according to their reaction is important. If you're looking to get laid and you open with a joke and get a bad reaction then just start being more direct flirty like going to grab her hand or asking to go dance (in a night club for example). If a girl says yes to going to dance with you then generally speaking that = Holding hands -> dancing -> grinding -> intimate touching -> kissing -> make your way back to someone's bedroom. Not all the time obviously.
If you're looking to get a phone number/a date at like a bar or supermarket or something, its a good bet to start with a question. Ask them to recomend the worst drink they can think of at the bar, ask them if they know how the hell you cook a Zuccucini and where to find one if your at the supermarket for example. People, especially women, bump into so many other people in any given day that you need to stand out and be memorable for some reason. Engaging in a conversation about some sort of bizarre vegetable can be a good way to get attention and then tell a terrible joke and apologise. If shes interested then she will engage in the conversation with you and answer your questions/laugh and cringe ar your joke (that doesnt always mean she FANCIES YOU, just that shes a nice enough person to humour you. Use some common sense). Complain about something silly like having lost your shopping list and that you're screwed because you lost a bet with your friend and now have to make him a romantic dinner, something silly like that.
Meander the conversation from that point to asking if she is busy later on/the next day/if it would be ok to get her phone number. Joke about needing her assistance again next time you go shopping or something.
Bare in mind people don't always react well to being hassled, if the initial response to your attention isn't positive or encouraging then respect their privacy and leave 'em alone.
picking up the ladies101