Spellcasting is an art some people born with this art or some people just learn from their guru(teacher). Spellcasting is a large subject but I am going to try my best to explain it in short. There are different types of spells for different purposes. But these are the most common things you must remember.
First of all, you must have protection or make one. Protection is very important because spells can backfire if the desire has its own protection. This is the most common issue for Asian people.
Secondly, the selection of a spell. Choosing spells is a big challenge for a new learner. Different situations have different spells then different spells need to be fit your situation. So, always consult your guru before doing a spell. There may have side effects if your spell is not going to fit the situation. These side effects most commonly appear for black magic revenge spells.
Thirdly, choose a place for your spell. Spellcasting must do in isolation conditions where no one can disturb you. A place where you are safe and where no one appears during your spell. If this happens in some cases you need to start your spell all over again.
Furthermore, Cleansing must important for some spells. Cleansing mostly requires for white magic spells.
Conclusion: There is a saying, “little knowledge is a dangerous thing”. You cast a spell if you know what you are doing. Otherwise, leave it there before it’s too late.
My Advice: Firstly you must take advice from a professional. If you can not for any reason then you must use an established spell. Established spells are always a good idea for beginners because the same spell has been used by many people.