A lot of people have given good tips for finding currently successful deck and cards; I would like to give suggestions for learning and discovering for yourself.
In the year and a half since I started playing there has been a strong trend toward very powerful gold cards which tend to dominate and shape the meta. There are multiple two point per turn engines, and engine combinations that can easily play for 8+. There are a lot of “remove or lose” cards. Because of this, there has come to be significant removal throughout the meta. And because of this, the focus has turned to cards that either distribute engine power over multiple units (e. g. swarm/boost combos), that generate carryover value (e. g. Erland), or cards that play for immediate value (preferably without causing any one unit to go too tall). Syanna and Damien are out, while Eist, Tunnel Drill, and Gezras are in.
Until the last expansion, the gap between top gold cards and bronze cards has steadily and significantly widened. (Given the push back against the recent strong bronze units, with no pushback against OP golds, I would not be surprised to see this trend continue.) Thus, deck polarization — stuffing a deck with low provision cards you intend to mulligan in order to fund as many top golds as possible — is the typical deck-building strategy. But this works best with tutors and thinning strategies to help draw the expensive gold cards.
I have chosen the route of crafting very few cards (only those I really want to play) and accumulating scraps to finally spend when I can get a complete set — that way I minimize wasted duplicate cards from kegs, but it means I cannot compete at top levels. From my limited perspective, I will attempt to identify good general purpose cards to recommend crafting — cards I expect will hold significant value across decks and metas; staples one can repeatedly turn to. Hopefully others will supplement/correct my list.
RECOMMENDED NEUTRAL CARDS
Heatwave
Oneiromancy
Curse of Corruption
Portal
Yrden
Triangle
Roach
Rockslide
Beyond these, there are numerous neutral cards are either fun meme cards (Syanna) or very useful in specific decks (Ciri Dash, Ihuarraquax).
Non-neutral gold cards are often deck defining — I would generally recommend crafting them with a particular deck in mind. But there are certain cards that have value in multiple contexts — I will mention those of which I am aware, but I can easily overlook cards that don’t fit my style or overvalue those that do. By the way, I do play all factions, but, right now, I am most comfortable with NR, SK, MO, and NG. I will not intentionally include cards in starter decks as they don’t need to be crafted.
GOOD ALL-PURPOSE FACTION CARDS
Echo Cards
Defender Cards
WoW Location Cards (available in reward trees)
Scenario Cards
Lock Cards
Purify Cards
Transforming Cards
Master Mirror cards with an “if order is not used” effect
8 provision special card tutors
OTHER MONSTER CARDS
Yghern
Naglfar
Caranthir
Ozzrel
Imlerith’s Wrath
Nithral
The Beast
Parasite
OTHER NILFGAARD CARDS
Joachim
Yennifer’s Invocation
Braathens
Vincent
Vilgefortz (meme?)
Henrietta (meme?)
Kolgrim (limited decks)
Artorius
Cantarella
Roderick
OTHER NORTHERN REALMS CARDS
Seltkirk
Prince Ansies
Queen Adalia
Keldar
Botchling
Flotest’s Pride
Vysogota
OTHER SCOIA’TAEL CARDS
Gezras
Vernossiel
Novigradian Justice
Saber Tooth Tiger
Servant Trap
Pitfall Trap
Treant Boar
Gaetan
Gord
OTHER SKELLIGE CARDS
Eist
Hemdall
Mordvark: Heart of Terror
Dracoturtle
Sigrdrifa’s Rite
Skjordal
Champion’s Charge
Raiding Fleet
Gigascorpian Decoction
OTHER SYNDICATE CARDS
Novigradian Justice
Phillippa Eilhart
Vivaldi Bank
Luiza
Sigi
Igor (meme?)
Moreelse
Flying Redanian
Tavern Brawl
Tunnel Drill
Whoreson Junior
Whoreson’s Freak Show
Gord
Cleaver
