Hey, welcome back to the Pokémon TCG; we're happy to have you!
Here are a few tips on rarity for a returning trainer:
Rarity symbols in English sets are the same as they've always been, ● for common, ♦ for uncommon, and ★ for rare. However, there are some new, extra rarities (typically represented by a silver ★ is more recent sets): EX and BREAK cards are the next rarity up from a holo card, then there are Full Art (FA) cards, followed by Ultra Rares (UR) which are the rarest of all.
- Regular EX cards have kind of a half art pattern with a Pokémon bursting out of the top half of the card, like this. There are also EX cards available of Mega Pokémon and these look similar but are preceded by an M in the card title, like this.
- BREAK cards are horizontal instead of vertical and feature a square holo pattern and a gold Pokémon render, looking like this.
- FA cards are alternate versions of cards, either EX, M EX, or Supporters. Like the name implies, they feature artwork that fills the entire card. They're much rarer than their regular counterparts and feature a textured pattern in the holo. Here is an example of an FA version of the Gardevoir-EX I linked above.
- URs tend to vary every few generations, though they almost always feature a gold border and post-set numbering, so they're easy to spot. In the most recent sets, URs are alternate FA versions of existing cards from the same set. For example, in the most recent set Fates Collide, here is a regular Alakazam-EX, here is the FA version, and here is the UR version, note the gold border and different style of artwork. Previous UR have included fancy versions of trainers, shiny Pokémon, etc.
Depending on how long ago you played/collected, you may not be aware of Reverse Holos (RHs), as well. RH cards come (almost) one in every English pack and are the same as regular Common, Uncommon, or Rare cards except that the background of the card has a foil pattern. In most recent sets, the RH pattern uses the card's energy type symbol as a design, like
there. You can't get RH cards of EX, BREAK, or UR cards, only "regular" cards. Also, when opening packs, BREAK cards are included in the RH slot, so sometimes you will get a BREAK card instead of an RH card. It is possible to pull an EX/M/UR card in the same pack as a BREAK card.
Of course, not all rares are created equal, with some cards of the same rarity being more expensive/sought after than others, mostly because of either popularity or competitive usefulness, leading them to seem more rare (Shaymin-EX is a good example of that). If you'd like to get an idea of how much certain cards are worth,
TCGPlayer is a great resource.
Good luck, have fun, and feel free to ask if you have any other questions!
