Make sure that you can make a decision on what type of playing cards you want to collect. Create a theme about your collection like celebrity photos, cartoon characters, historic places, patterns & textures, etc. You dont have to limit yourself to certain subjects but having a theme creates a challenge or a basis to make it exciting. Just remember that the collection doesnt have to be costly, it is valuable only to the collector, which is you.
Base your collection on shapes out of the ordinary such as playing cards shaped like an egg, or round-shaped, or even star-shaped.
Purchase those cards that are not usual like the Apollo II deck, cards printed with shocking adages or about history. A great addition to your collection would be anything that is rare.
Find cards that provide facts about history, informative lessons that add to the knowledge make your collection not only interesting but also an opportunity to learn something new. Opt for cards with a certain monograms like a Gothic monogram or a floral monogram or an ornate monogram.
Keep your options open though. You might find that your collection only leads to a blank wall. Your chosen theme is probably very rare.
Sports themed playing cards, like baseball or football, are quite common, easily obtainable but a lesser challenge.
You can also find unusually sized decks like minutiae cards as small as 1” by 2” or giant sizes as big as 6” by 12”.
Be on the lookout when on a vacation. Youll never know what crazy idea somebody from another country has come up with. The difference in your cultures makes foreign peoples way of thinking more interesting. Most commonly you can find novelty/souvenir decks, from local tourist sites to fanciful courtesans, from literary commentary to historical recreations, from political satire to local surrealist art.
Don't think twice to show your collection to friends and family. Tell them about its theme if you are very strict about it. You will find that they would be most happy to give gifts that would add to your collection.