You sound like you are taking the right steps to work with spirits! I can't tell you what will work for you, since summoning is very personal. But I can tell you what I do personally! When I want to work with a certain spirit, I always research that spirit's mythology, history, and everything I possibly can know about them. This includes the culture of the society the spirit comes from.
Once I know a little more about the spirit, I will start designing a tiny space for them based on their culture or environment. For example, I am mostly an animal spirit person. So if I wanted to attract a badger spirit, I would build a tiny den out of paper mache, paint it beautiful colors, research what badgers like to eat, leave it as offerings at the space, go to the space often to talk to the spirit, ect. For non earthly spirit, I would do the same. For example if I wanted to contact a water dragon, I would build a little tank and decorate it with quartz, leave fish offerings, ect.
One I have a little place for the spirit to be received, I would start the initial visit. This is where I just sit in front of the space and invite spirits to join me. Always act respectfully towards the spirits and keep your head bowed. You don't know if the thing you are talking to is a spirit or some forgotten God (and having a God mad at you freaking sucks, let me tell you what.)Get to know the creature that comes in front of you, ask if it likes the altar you made for it, ask if there is anything the creature may want, ect. Get to know the creature and form a bond with it.
Once you have a bond with the spirit it is time to take out your handy dandy vessel. A vessel is just an object that a spirit either lives in or is an object that will summon the spirit when needed. For me, the animal gal, I would use a bone or pelt of the animal to vessel it. But a piece of jewelry or a jar would do just fine. Go to your altar and talk to the spirit about forming a contract/agreement/whatever your particular path calls it. You may want to write the agreement on a piece of paper if it has rules, or the spirit may just want to be your companion and be happy to do whatever you want. For example, I worked with a dragon that agreed to work with me only if I offered it rabbit meat every Sunday, while I have a cat spirit who basically jumped into the vessel as soon as I asked and hasn't left since. Either way, once you have determined what type of relationship you and the spirit will have. Invite the spirit into the vessel and bind the vessel with either you blood or spit (be careful that the spirit's culture doesn't take offense to spit! Animals don't care, but mythological creature can be a bit more stern). Always ask the spirit how long the contract will last, keeping a spirit longer than agreed can cause a lot of drama in the spirit world and you just don't want to deal with that craziness. Then bam, you got yourself a spirit companion. Remember to give it offerings and attention everyday, even if it is just a glass of water. If you need anymore help feel free to message me!