This guide is for players who are new to yomi. If you're not sure why one thing is better than another, or yomi feels too much like guessing, this guide might help!
The tips in this guide are all rules of thumb; they don't apply all the time. Some exceptions will be listed and as you get familiar with the game you will understand when to break the rules. Before we get to breaking the rules, first let's learn them!
Basic Game Flow
Attack, throw, block and dodge. The value of each option changes at different parts of the game. Knowing when each option is most useful can help you decide when to play it or expect it from your opponent.
Early game: When the game begins, blocking is powerful. You start with a random hand and probably need help finding cards to do good combos and power up for aces. This makes throws appealing for damage in the early game. Attacks are risky because it is unlikely you have a good hand to convert attacks into damage. Meanwhile, a blocked attack lets the opponent get a large card advantage which could be trouble later on. Dodges are weak here too: on the off chance that the opponent attacks, it would be better to get more cards.
Mid game: Blocking becomes less valuable because both players should have good damage options in their hand. This is the time to convert cards into damage with throws, or catch the opponent's throw with an attack. Blocking is still good as protection from fast attacks and hand management but is no longer vital. Dodges might pop up here too, since it's a safe way to land ace attacks.
Late game: Blocking becomes very weak when life totals are low. It's likely that either player can win the game with the cards in their hand already, and don't need more cards. Conversely, dodges become very good! A simple dodge into throw might be enough for the win. Fast attacks and dodges are the most valuable moves here, making throws risky but relevant.
The value of cards
Different cards have different values, even if they have the same options on them. Here are some ways to spot the best options.
Attacks: Slow normal attacks are a poor choice for combat. Anything speed 3.0 or slower is considered slow. Most characters use certain face cards or at worst their 2 attack since they have a good chance of beating other attacks.
Exceptions: When an opponent is knocked down, normal attacks become much stronger since they have a chance to beat blocks. Rook has so many powerful throws that it's often necessary to use slow attacks just to avoid being thrown.
Throws: Throw speed matters a lot! Many characters have throws from 7 to 10. A throw's speed is based on it's rank, so 7's have 7.X speed and 10's have 10.X speed. This makes 7 much better than 10, since 7 will often beat other throws and 10 will often lose to other throws.
Exceptions: Rook and Midori have many fast throws, so throw speed doesn't matter as much when attempting to throw them. Lum has a fast 6 throw.
Blocks and dodges: Believe it or not, there are good and bad blocks! What matters is what is on the other side of the block. A 7 with Block/Throw is valuable as a throw, so try not to risk it by blocking with it. Meanwhile, a 10 block/throw or 5 block/attack cards are less valuable, making them excellent for blocking. The same rule applies to dodges.
Exceptions: If an otherwise weak block card has an ability on it, the card may be highly valuable. For example, Grave and Valerie's 10.
Reckless play in yomi can quickly lead to a small hand size. To avoid being stuck with no good cards, here are some quick hand management tips.
Try to keep one of every option in your hand. It's easy to take advantage of a player if you realise they have no blocks or throws left.
Avoid being stuck with 1~3 cards in hand where possible. The less cards you have in hand, the less scary your attacks are and the more you need to block. This makes it very low risk for the opponent to throw every turn. When fighting Rook or Midori, being 'throw looped' in this way can be devastating.
Don't follow up throws with combos in the early game. Those cards can probably be used in a combo later and may be useful as blocks right now. Following up a throw with a very low damage combo such as throw > 2 > 3 is usually a bad call, since those cards may be better off being saved to power up for aces or used as dodges. Don't underestimate the power of a simple throw with no follow up for a knockdown.
When powering up, remember that pairs retrieve one ace but trips retrieve two! Try to save up for trips unless an ace attack is urgently needed. Also keep the value of cards in mind too - powering up 7 throws might lose you the game, but powering up 10 throws is usually fine.
Jokers and bluffing
Jokers are valuable tools which makes misplaying them especially bad. Keep the following in mind when using jokers:
Rewind Time is usually the better option. Preventing a powerful midgame combo into aces can win the game.
Gold bursts are excellent in specific match ups. Characters with small combos don't care about Rewind Time being used against them, so hit them with more aces instead.
Don't always bluff! It's fine get hit by a combo, particularly early game when both players have low damage in their hand.
Don't bluff valuable material away! Abilities, aces, fast throws and good face cards - bluffing those away might be as bad as taking damage. Bluff with cards that are less important.
Time to start winning!
If you didn't know all these rules of thumb before, you may find your winrate increases dramatically when you take them on board. Good luck!
Perhaps this image might help?