Simple decks are the BEST like the Blue Owl - no poems.
Understand each cards meaning first - as in a base meaning for each one.
Learn the differences between systems, but follow one. The FRENCH is lighter than the GERMAN system to some extent as well as the BELGIUM one I'd say. And ALL are LESS heavier compared to the Brazilian system which is steeped in "spiritual" and "magic" rituals etc.
I do not think too much of the Matthew book nor what I saw of Donnaleigh with her "38" card GT.
Remember GTs are only 36 card spreads.
Steinbach I feel should not be ignored as she does provide value with a lot of two card meanings in her book, however, her system is hard to grasp and therefore her book can cause confusion.
Rana George from what I saw was okay, but that was just one little video. Have not looked at any more yet. Have seen parts of her book and if you are fine with lots of personal stories as well as spreads and meanings - then it is probably the one to get out of all of them. Andy B use to be on AT and he uses the German system. It is a little more harsh than the French, but it also uses the "far" and " near" method in the GT which was my teething ring.
You are lucky there are a lot of resources available these days, but because of that it does cause some confusion. What I find interesting is how some do not know how to apply the cards to different situations or they read them like they are Tarot. So, it makes me wonder if it is because of learning from a PC or book rather than a person, or how they learn.
Keep to the basics is my advise, stay with the question, and do not add unnecessary crap. LEARN how to apply the cards to different questions like the HEART should be different in a LOVE question compared to WORK. The mistake I see a bit with readers is when they take it somewhere else completely when they see cards like HEART or MOON or FOX because they see those cards in a specific way.
DND