I'd like to share my experiences with doing invocations. I like to come up with my own ritualistic practice a lot and invoking things works really well for me. Me personally I've invoked Hecate and Lucifer with my own material. It actually worked for me and I've spoken to these deities through dreams, I think the key is to actually believe something will happen.
But I like to try things with a opened mind. The best way for me to come up with good material is to go through a chaotic process and see what has worked for me. I am also a tarot reader. I don't like to say this and that is not possible either I am open to possibilities. But if I haven't seen it, it will be hard for me to believe it. Try this one invocation that has personally worked for me.
(DISCLAIMER: It may not work for you this is a chant to Hecate and she may or may not want to communicate with you or that is not what works out for your psychological workings.)
So here's one of my invocations it's a rather simple invocation that you recite 3 times: Soul white as day heart black as night let the crone come into my might guide my way and direct my sight I am Hecate I invoke your rite. 3x
Hecate is also known as trivia and Phosphorus is another name for Lucifer which is the two deities that has noticed me so far and depending on what relationship I can build with them will be wether I can give out more material I'm just good at invocation so far so why not share my experiences.