4. Don't use cards that deplete your hand or give you drawing
disadvantage. Stay away from Magic Jammer, Tribute to the Doomed,
Offerings to the Doomed, and any other card that requires you to lose
2 cards to stop or destroy 1 of your opponent's. Unnecessarily Running
yourself out of cards is generally a bad strategy. Use Fissure instead
of Offerings to the Doomed, and Magic Drain instead of Jammer. Cards
such as Horn of the Unicorn and especially Cockroach Knight should be
avoided. By adding in cards that come back to the top of the deck, you
stop yourself from drawing any new, better cards, and that can really hurt
you in the end. To go along with that, Equip Cards in general aren't good
to use (Premature Burial and Snatch Steal are the exception). They drain
your hand too quickly, and it's easy to destroy them. Let's say that
you play 2 Axe of Despair on your Harpie's Brother, then attack. Your
opponent flips Mirror Force. 3 of your cards are destroyed, and they
only had to use 1. Lets say that you instead have 1 Axe of Despair on
your Harpie's Brother, and you attack an opponent's Jinzo. Your opponent
flips Mystical Space Typhoon over to destroy the equip, and the now 1800
monster is destroyed by Jinzo. You lose a monster and an equip, your opponent
only uses 1 Magic Card.
5. Don't add in mini-specific-combos. What do I mean by
this? Here's an example: Don't use 1 Insect Barrier and 1 DNA surgery
in your deck. It's very unlikely that you'll draw both in any given
game. If you do plan to use a specific combo such as that one, use 3 of
each card, unless one of the 2 cards has a second reason for being in your
deck. In the case of Umi/A Legendary Ocean in a Water Deck, 1 or 2 Tornado
Wall instead of 3 would be ok. As you get further into the game, you will
probably find that most of the specific combos don't work that well, and
that your deck improves when you replace them with cards that don't depend
on each other so heavily. I didn't start really winning tournaments until
I took my Flash Assailant/Reverse Trap (3 of each) combo out.
6. Try to keep a good Monster to Magic/Trap ratio. For
people who are just starting out, I recommend that you make your deck a little
less than 1/2 monsters, except in special cases. In decks that doesn't
win by attacking, you can get generally get away with using fewer monsters.
7. Don't use too many Tribute Monsters. I cringe everytime
I see a deck that has more tribute monsters than non-tribute monsters.
I understand that a lot of people don't play in tournaments and don't
have a lot of cards, so they play no tributes. If that's the case for you,
don't worry about this section. For everyone else, I recommend using 3
Tribute monsters at the very most, unless you run a deck (such as a Black
Skull Dragon Fusion Deck) that requires certain Tribute Monsters to be
effective, or has a way (or ways) to easily summon them (such as the upcoming
Dark Magician/Dark Magician Girl Support Cards). This also includes cards
with Special Summon Requirements. I wouldn't use more than 2 in most decks.
In a Dark Necrofear Deck, 3 Necrofear is ok. In an Earth Deck, I wouldn't
recommend 3 Rock Spirit.
8. Avoid life gain cards. If you don't run a Fire Princess deck,
don't use them. Solemn Wishes gives you 500 per turn, a Gemini Elf can attack
for 1900. You'd have to draw cards 4 times to gain enough Life Points to make
up for 1 attack. If your opponent attacks your empty field, Enchanted Javelin
only cancels the attack of 1 monster (unless the monster has an effect such
as Yata-Garasu's, then the monster's effect still happens). If he/she attacks
a monster in defense mode, you still lose the monster (assuming that its
DEF is lower than the attacking monster's ATK). Field advantage is lost,
and Card Advantage is sacrificed for Life Point Advantage. Your opponent's
monster can attack you again the next turn, and you have 1 less monster
to protect you from a direct attack. If you want to use a card to save your
Life Points, use Waboku. It gives you field advantage by protecting your
monsters from attacks, and it protects Life Points as well. If your opponent
uses a Heavy Storm or Feather Duster, you can chain Waboku and your
Life Points and monsters are still protected. Cards that only increase your
Life Points don't hurt your opponents in any way, and it makes it easier
for them to run you out of cards to use, and/or get you into a Yata-Lock.
Don't sacrifice Card advantage and/or Field Advantage just for Life Point
Advantage, it'll hurt you in the long run.