Improving in meditation skills is both easy and hard. The easy part is you just have to do it. It’s a skill and practice makes perfect. The hard part is achieving your goal, especially if you have a.chattering mind and can’t sit still easily. Remember that you can also meditate while doing repetative things like walking, doing dishes, even sanding down wood.etc.
It depends on the type of meditation, but the most common “quiet your mind” meditation is basically just starting slow and try to achieve a quiet mind a minute (that took me 15 to 30 mins of meditating at first) and then gradually increasing the time.
I think this can get you started nicely. I know it helped me improve really quickly when I just started.
Actually if you want black magic specific stuff. Mr. Conner Kendall has shared loads of stuff on this forum, from rituals to guided meditations etc. Search for his name and scroll.