How to express tactfully one's intentions or needs? To marry intention with action - this is a life skill. If we do not have someone to model after to train this skill in the context of the subculture in force, we are bound to make social mistakes casting around for appropriate way to express ourselves.
Establishing rapport is the most important ingredient. Deciding how to pop the question that may accelerate a "non-obligatory" state of friendship into reciprocal give and take is tricky. Key seems to be noticing how people treat their friends with whom they have already established trust of this sort.
Usually, the answer is often that there has already been a "give and take" in the context of the relationship that you may have missed noticing. Each person has a certain language of bonding built out of unique combination of experiences they find essential to establishing trust. Trust in this context is earned, not a given - although many people will declare that they tend to offer strangers the benefit of the doubt until proven otherwise.
For some people this is attending school with them; for others it is working together. Some cannot trust you until you find out a revealing secret and forgive or ignore it; some keep you away until they have a need so great they must ask for help. As they realize you are stellar at offering what they need and they also find out the offer was not an "exchange," it wakes them up that the two of you have established what connection means. Sometimes establishing this connection can happen by merely emulating the way their family members and good friends treat them - gradually. Sometimes this connection is just that the two of you have more to talk about, or that you sense some aspect in character in common or differing in each other that you'd like to explore.
Sometimes I believe there are people who create energy from being with others and spend it on accomplishment...and people who get energy from doing things and spend it on relationships. It is the category of people who love to do things and spend it on relationships, the more dynamic ones who are dangerous. Sometimes people who like to accomplish things are lousy at relationships, because they're somewhat scared of intimacy. You would want to make sure you are NOT making a deal with this sort of person. Otherwise you might get lost in an endless "deal-making" competitive activity with some "aftertastes" of hidden agendas.
Whereas, with people who are into "hanging out," they often have no problems being generous with their time because they will be getting a benefit from your presence, without any directed benefit. No "invested interest" or agenda, in other words. It was modeling those connecting people can allow a dynamic person suggest to "take turns" benefiting each other to establish a warm and fuzzy feeling of mutual benefit.