Modern folks like to call upon God to send His arch angels such as Michael for help directly. Though this is not logically wrong in our human eyes, the 'procedure' is wrong. The proper way is only to pray to God solely and let Him decide on who to send. So don't be surprised if Lucifer came instead of Michael.
I called upon angels in the name of God but Lilith came instead. So don't be surprised!
Even I am not a believer and I have some kind of angelic contacts after praying to God thanks to the true 'Key of Solomon'. So, if a believer follows the instructions correctly without compromising the quality, then he/she should have a better experience than mine.
The quality control in this sense is the sincerity, the sacrificial materials such as meat, frankincense or myrrh and most important of all, a thorough understand of the holy books and the intentions of God.
Prayers can be made any time and any where if one is only seeking for the console of the heart. However, I would personally burn some meat together with some frankincense in a bonfire because this will result in some kind of manifestations. Of course, not everyone agrees to it.
To me, KISS principle suits modern conjuration very well. Where KISS stands for 'keep it safe and simple'. There is really no need for cryptic symbols, seals or magic squares. What is not written in holy books should be forsaken.
Just a point to remember for non-believers though: Avoid praying to God in a place with many idols or the consequence will be catastrophic. At least 7 days before praying to God, refrain from intimate acts. And most important of all, absolutely no adultery please.
God will not punish a non-believer if he/she does not pray to Him. Howver, anyone who prays to Him will automatically be His believer (naturally) and he/she is subject to punishment. Try to pray to God you may, but watch the rules of the road please.