Being in a team and doing team work can get confusing and complicated. It can turn into utter chaos. Things don't get done or may even get ruined. And what could and would have been comradery, turns into rivalry or worse. This will largely depend on the maturity and disposition of the members, but having a set of rules and guidelines to adhere to or consider may help those willing to put in the effort.
Be helpful or stay out of the way.Acting as though you are involved and participating isn't necessarily contributing. If members are working on something, alone or with others, don't come in just to cost them extra time and energy (maybe even resources). If you don't know how to contribute but wish to, ask for instructions and follow them. Alternatively, give space if your offer is refused.
If a task at hand is delicate and/or risky, proceed with caution or hang back.
Not everything that looks easy is. Not everything others can do you can do as well. And there is no shame in that. Leave these things to those qualified to handle them. Assist under their direction if they find that beneficial or step back if they don’t.
Get to the point and speak clearly when merited.
Doing so goes a long way. Conversations, discussions, debates, or even riddles may be welcome and appreciated, but you must pay attention to when that is or isn’t the case. When people are busy, tired, rushing, or, for whatever reason, not that into you and what you have to say, do them the favor of being short and direct with your message. Let expanding on it be optional or neatly summarize and highlight key points for them.
Reflect further before becoming resentful and hostile over what looks unfair to you.
People tend to reduce and twist the meaning of fairness. To be truly fair, innumerable factors must be taken into account. Just because there are unequal treatments and expectations among the members at a given point, it doesn't make it unfair. Some people are at a disadvantage and are therefore provided with accommodations, some already did their share and can take it easy, some have impediments to be as present and active as others but do their job anyway so it is okay, some are still clueless (but learning and applying) so they are allowed more mistakes, some have more taxing roles than others thus are kept from inconveniences, etc. Running the opposite, some have repeatedly performed poorly for no good reason and have fallen from grace or similar.
Have your trust issues in check.
If the whole team or particular team members have consistently shown you that they are trustworthy (by being competent, responsible, discrete, and more) and you still doubt them, you are the problem. They are under no obligation to continue proving to you that they can be reliable. Incessantly doubting them and submitting them to scrutiny and examination might bring out sides of them, out of exasperation, that would have never come out otherwise - to then confirm your bias thanks to your self-fulfilling prophecy.
Leave shallow comparisons and competitions out.
Even if that’s how you are and how you roll, it is not conducive to good group cohesion. Especially if various members do not care for vanity or are even repulsed by it. If this sounds like too much of a sacrifice to you, being a team player might not be for you. Or at least not as a member of a diverse team of people who aim to build each other up rather than tear each other down.
Avoid excessive or inappropriate flirting (and lustful behavior).
It may seem innocent and harmless to flirt with others, but it rarely is. It can be majorly distracting and delaying. It might also be disrespectful to the other person and/or their partner. Even in cases where it is indulged, the work setting is not the place - it can make one, the two, or others uncomfortable when it goes on for long or beyond tame public displays of affection. Take that elsewhere. If you are a naturally flirty person that simply and normally operates like that, make that fact obvious so that it is understood in that tone alone.
When you have gravely upset one or more members of the team, time out yourself.
If you were in the wrong, recognize your faults and shortcomings, offer a genuine apology, make suitable amends, and let it run its course. Do not force yourself onto them. Chances are they will be irritated by pretty much anything you do, no matter how benign, until they have fully recovered and come to terms with what occurred. Even if you fear losing connection, it is best to put some distance to not make it any worse. Make it evident, if it is the case, without pressure, that you are not ending things and are only giving room.
Work is a duty, socializing is not.
It may be ideal for you to have a friendly and inviting environment where everybody gets along and is happy to spend time with each other outside of work and working together. However, some people prefer to keep socialization to a minimum for personal reasons while committed to being a good team member in other aspects. Do not demand more of them than that. It may be an act of sself-preservationor of optimization. Not everybody is boundlessly social (and nobody is required to be fond of you).
Pass leadership to the rightful leader.
Being in a leadership position can be enviable, for it is interpreted as a status symbol and the privileges of it may seem enormous. But strip the perks and compensations for it and what you have is more work - even if that work isn’t immediately evident. The leader is someone capable of moving things forward in a constructive direction, carrying the weight of making fruitful decisions. This can depend on what the challenge is rather than on a single set of fixed qualities. So who is a leader in one area may not be a leader in another. Be humble and flexible enough to let leadership switch around as necessary.
Be considerate and respond to requests.
It is not about being blindly obedient nor about bending to others’ wishes whenever and however. It is about being cooperative as a teammate. Not many enjoy giving ultimatums, raising their voice, making threats, and kicking people out. If the request is reasonable and justified, don’t let it get to that point by being self-centered. If you cannot or will not tend to a request, be transparent about it in a timely fashion so that it can move to another person.
Give credit where credit is due unless sources prefer to be anonymous or consent to not receiving credit.
Not only is it unprofessional to take credit for others’ work, it is also embarrassing. It denotes an inability to own up to and accept what you brought to the table, no more and no less, and the desperate attempt to make yourself look bigger than you really are. Furthermore, most people can tell when something is a collaboration or a derivative, so you’re making yourself look bad by failing to share credit or even trying to cover it up. If the work you’re being praised for or benefit from is heavily reliant on others’ efforts, at one point or another, you must arrange with them whether or not they should be brought up, how, and when.
If these rules and guidelines apply to the type of team you’re in, keep them in mind or at hand to revisit them and abide by them.