I looked through my journal to see what I've learned last year since we started a poly relationship in the spring. I didn't think the list would be this long, though... Sorry about that.
No wonder I feel like it's been an eventful year!
I am writing this all from the perspective from opening up an existing relationship to start a poly relationship, since that's my experience.
a. I need to give a lot of thought to my own wants and needs, and work on making my own boundaries. I am responsible for that, and it will benefit not only me but my partners as well.
b1. The concept of 'wanting the relationships to be equal' can perhaps be a useful approach to make sure there is consideration for the new partner/relationship and for enabling changes that are necessary in the beginning of a poly relationship. However, at some point you need to move from "fair" to "what everybody involved wants and needs" in order to create relationships that bring the most satisfaction for everybody involved. (And the point a. is important in this process: you need to know what you want and need to do this.) Also, equality is not sameness or symmetry.
b2. Related to that one. Equality/fairness perspective has an inherent assumption of entitlement. I.e. because my partner has x my other partner should have x, too, otherwise it's not fair. There is a problem with that, because really it comes down not to what the other person has, but what all involved want.
b3. Opening up and starting a poly relationship, you cannot be opposed to change in your original relationship. You will no longer be 'a couple' but three, or more people. However, you also shouldn't strive for equality right off the bat. It is useful to think about the time it takes in a new monogamous relationship to entwine lives. It will take more time in a poly relationship, because there are more people and lives involved. You should let things develop in a pace that feels comfortable to the direction they want to take.
c. It is ok to feel odd and awkward with things. Those feelings will come up with poly since we are socially conditioned to monogamy, but they will always pass with time, and poly becomes the new 'normal'. The feelings also must not keep you from communicating.
d. I am good at taking into account and balancing my partners' needs, even in NRE. I need to work on is recognising and taking into account my own needs just as much.
e. The importance of living and being present in the moment cannot be overstated. I want to concentrate fully on whatever it is I am doing at the moment to enjoy it. For this again the point a. is important: I need to have boundaries and decide to engage with things when I have the energy to be present doing them. E.g. I need to have enough time for myself to be able to be present and enjoy the company of a partner.
f. No matter how long you have been together with your partner, there are sides to them that are new and interesting. Everybody changes and evolves. If you feel like you already know everything there is to somebody, make the effort to get to know more of them.
g. A monogamous person can be completely happy and satisfied in a polyamorous relationship where their partner has other partner(s). There can be total acceptance of each other, and it doesn't always require tons of painful work to get there. There will be some uncomfortable feelings to work through, though. (I am not trying to disregard the experiences of the people who find the transition extremely difficult, or never get to a comfortable place in a mono/poly relationship. Just saying that mono/poly can work just fine for all involved.)
h. It is good to ask for what you want. If you want a hug, you can ask for it. If you want to hear "I love you" more often, you can ask for that. The fact that your partner didn't read your mind and spontaneously do what you wished for in no way lessens the value of the sentiment. If you can let go of the belief that people in love should read each others minds, you can communicate what you want to feel loved and truly enjoy it when you get it from your partner.
i. I need to trust other people to communicate their feelings to me. It creates huge amounts of stress to try to guess. Also, if I do guess, it creates a disincentive for them to talk to me, since I seem to be able to read their mind. I do not want to be responsible for the communication alone, therefore I need to wait for my partners to choose to talk to me, even if I do have a feeling there is something going on.
j. When your partner feels jealous, insecure or other negative emotion, you may feel hopeless. It is important you don't let that emotion to take over, so that you can be there and support them. You should also remind yourself that the feeling of hopelessness is not based on reality. Even if you feel like, at that moment, no progress is being made, that is not necessarily/likely true. Just because your partner feels hurt doesn't mean they will keep feeling it. It will pass, and likely become less intense and come up less and less often in time, as they are working through it.
k. Metamours need to be able to communicate directly. The importance of this cannot be overstated! It is ok if some information is passed on by the shared partner, but there needs to be a shared understanding and commitment to direct communication when it is needed. I addition to communication, it is helpful if metamours can get along and care about each other's well being. That is all you need in a metamour relationship. If there's more, that's great, but you should let it develop on its own and to the level that feels natural to all involved.
l. When a partner expresses hurt feelings to me, they need support, not for me to fix it. I need to set aside my rational responses to their possibly irrational feelings, and be there for support. I can bring up the rational later if it seems it could help, but not before they are ready for that. (I am so bad at this, but I'm trying.)
m. No matter how much thinking you've done about poly, and how much your partner tells you they are ok, there is likely to be guilt when you first start a relationship with somebody else. You shouldn't let that guilt dictate your behaviour. You need to trust that your partner will tell you if something is bothering them.
n. I've always approached my friendships as an individual, not as a couple. Thus, it has felt natural to do the same when it comes to romantic relationships. I think this has helped me in poly. I don't change my approach around how I make plans or what I do. For example, I always schedule meetings with friends alone and just inform my husband about the fact that I wont be home at the time; similarly I schedule meetings with mygirlfriend and inform my husband about that. I don't think the nature of the relationship should make a difference in terms of control, in that I would suddenly start asking for permission to go on a date or something like that.