I’m actually in the middle of making my own deck right now! If you want professional-looking cards, you’ll need a proper printing service. MakePlayingCards is what most people use for single decks. Just know that shipping takes a while since they’re in China.
Skip their recycled cardstock though. The cards feel soft and thick, kind of like bar coasters, and they have this weird greyish-pink tint that doesn’t look good with colorful artwork. You pick your card dimensions first and download their PDF template.
Then, arrange your designs in any graphics software to match the template. You want 300 dpi resolution, Instagram screenshots won’t work, so find better quality images. Add whatever text or titles you want, export it all, and upload to their site.
Maybe start with just the 22 Major Arcana cards instead of all 78. Or make an oracle deck, there aren’t any rules for those, so you can do whatever number of cards you want. Oracle decks usually have quotes or phrases on each card, so you could use inside jokes, song lyrics, whatever. Add astrological symbols or numerology if that’s your thing.