I am currently listening to an audio book called 'The Like Switch' and in it describes exactly your scenario!
People like to hear their own name according to Dale Carnegie so perhaps using their name enough that it doesn't sound false. Also proximity and duration is important. Make sure you are in there line of sight quite often and give off friend signals such as the eyebrow raise, perhaps a slight touch on the arm.
Empathic statements are great tools also to make it seem that you are on the same level as them as they can then engage in conversation. Active listening and encouraging the person to see you in a positive light by sending friend signals that I stated above will work wonders.
Just watch the 'spotlight effect' which means that you think that everyone will know exactly what you are up to and will see that you are trying to manipulate them thus making your actions seem incongruent and not natural. Practice on others so that your friend signals are not forced.
Using these examples you can friend anyone