In a perfect world, friendships are quid pro quo. But in reality, they aren't. Someone is always doing more than the other in some way at any given time. It doesn't register most of the time, because you genuinely appreciate the other person in your life and don't begrudge them your time or energy.
So the next step is:
Making Friends Step 3:
Finding balance as you build
It is perfectly normal to expect others to give as much as you do in a relationship. Whether it is familial, friendship or romantic, there must be balance in the exchange. Otherwise it becomes one party using (and often abusing) the other. There's to formula to it, however, and you have to establish the rules as the relationship builds.
For instance, if you are the type of person that needs regular contact to feel connected - you may have to be the one to call, email, or drop by initially. Everyone has different contact needs. Because of this, the other party may or may not be always available but there will be a sense of regularity if you are consistently in contact.
I caution you to pay attention to the signals others give you. If the person begins to shy away or cancel arrangements regularly, perhaps the contact level is too high for them. It very likely is not anything personal with you, but a need for space they possess. Always respect that in others for it's likely you will have a time when you need space.
If you are a person that does not need regular contact, that's ok as well - but be aware you may come across as aloof or disinterested. In this case, a simple acknowledgement of the contact and promise of future interaction (with an actual event or date / time attached to it) will go a long way to reassuring new relationships that you are still actively interested.
Along with the building of contact in the relationships, you will begin to find yourself with a full calendar. Suddenly there are details about other people you need to remember and details about yourself that will be shared. The longer the relationship lasts, the deeper those tendrils of interweaving go. Your time will no longer be strictly your own, simply by the obligation of the relationship.
This can be a dangerous point. People tend to go to one extreme or another. Either they lose track of their own personal boundaries, needs, and plans so they can meet those of others; or they panic and cut all contact because they fear losing those boundaries. Both result in resentment and detachment in the relationship. I cannot advise you ever sacrificing your personal boundaries and needs for anyone else. Your born into this world with a primary gift - life. You life (and all that makes it work) is yours to grow and protect. It must come first for anything else to be healthy. While I firmly believe that the spiritual part of your life comes first, then the mind, then the body - you must decide for yourself what those boundaries and needs are.
Another important element is that of give and take. Be conscious of how much you give and take in any relationship. Whether it's emotional or physical support, monetary support, time, effort, or space - know what sort of space you are occupying in the lives of others. So many times I have seen relationships fall apart because of a general lack of awareness on one (or both) parts of how they were affecting the other person. The internal focus on "what it does to me" often blinds us to how we affect others. By the time we can see that we are either negatively affecting someone or they are affecting us, it is often too late to avoid a break in the relationship.
Caution and communication avoids most loss of balance. As a relationship ages, funny enough, the contact levels tend to decrease and the comfort / security levels rise. You don't need to see or talk to the person as much. Perhaps because you truly know and trust them now, so you're not wondering if they are still "your friend"? Perhaps because you gain confidence in your role in the relationship and are certain of your place in it? I don't really know why, but it seems to work that way pretty much every time.
Now all this is simple and positive, but there are going to be some rough spots. There is no good without bad, so expect arguments and agree-to-disagreements. Expect some people to fall off the radar or walk away. Even if you're doing everything right, perhaps that person is not in a place to give or receive just now. Life events can cause changes in people midstream. You can learn more about someone and discover fundamental issues you cannot handle or accept.
The key to step 3 is that you are still practicing steps 1 and 2. Your life circle will always be evolving. You will have those people and elements that stick - but you will have a much fuller existence with the other relationships you build along the way. Why? Because they enrich and grow you. A You everyone who stays in your life gets to enjoy as well.
I have been blessed with some pretty great friends that I have had for years. I have some people I can reach out to that I haven't spoken to in ages, and it's like no time passed at all. There are many friendly acquaintances in my life who may only be here for a season, and that's ok. All of those relationships and the experiences within them help make me who I am. I am not unique or especially amazing, but I've learned to cultivate relationships as best I can. So far, so great!
There is only one more step in making friends and it's no fun, so we'll save it for another day. For now, enjoy the people in your life. Enjoy the life you build as you build the relationships. Mostly, revel in and remember the experiences because they are the building blocks of your life.