Instead of focusing on evocation, where alot of preparstory work, tools and weird stuff is most required, you can work with invocation. Hell, all it takes for you to invoke a spirit is your mind, focused and strong will and learning how to use your bodly tensions/relaxations to improve the technique and draw even more energy from spirits.
In 3 mins you can do a whole invocation:
Focus your mind on the spirit you want to invoke.
Keep it steady. When some tension starts to build around and in your body and mind, its a sign the Universe is manifesting the spirit to you.
When a decent amount of energy builds around you, or above you, or anywhere you feel it coming from, draw it to you. You can use body moves like Tai Chi to help out if you feel like a good idea, personally, I like that.
If you can apply some bit more complex concept to all this, you can use the principle of Equivalent-Exchange, thats is trading a part of you for a part of the spirit. You’d be astonished on how some of our crap can bring real gold from spirits. They are meant to help mankind to reach godliness after all.
Start with some angel, either Sandalphon or Gabriel would be great as they are from lower spheres, being that Gabriel tends to cleanse alot of junk from our subtle systems and psyche. You can start from above and try this with Metatron, but the energy shift is so intense that may actually be a burden to handle it. Besides that, such a high-frequency energy aint much applicable in the beggning for more practical and earthly purposes, they are more suited for inner alchemy and commanding other spirit, seems to be good for HGA operations also, but Im not sure about this. My personal practice is to work with both the above and the below, so theres always balance in my Universe and my Inner God is always manifest and potent.
And thank you for the cumpliment, Lady Eva 