I notice, from personal experience, evocations and invocations work better once i started doing the Wim Hof method, ice showers, prior to meditation and rituals. i also tend to say a mantra as I do this, like a positive affirmation of cleaning away not just dirt, but doubt and desire. I’ve told a few people about this method, not for magickal purposes but to clear their minds over stressful situations in their own lives, it seems to help them out.
Also to add to @anon37593562 the gallery of magick library is very affordable and just chocked full of easy to digest well written ritual and workings, demons of magick is top notch.
Another book to recommend to beginners, check out Miracle of the new avatar power by geof gray cobb, worked the rituals plenty of times with success, its an easy system for beginners and helps to establish the meditational and ritual habits. No sigils required for the workings and words of power are written phonetically so its easy to recite and remember.