Test, test, test! This is where Forge becomes an invaluable tool.

Do your best to avoid dead draws.

Every turn, do something that applies pressure to your opponent.

• deliver damage
• make them discard
• remove a creature
• prevent them from casting a spell

• Why does this card deserve to stay in the deck?
  • What purpose does it serve?
  • Is there a cheaper way to do it?

Which lands you put into your deck are as important as (if not more important than) the spells, creatures, and artifacts. Without the right mana at the right time, you won't be able to cast the spells that make up your deck.

While the following article does not mention the use of fetch lands in conjunction with shock lands, it does provide a good overview of the importance of a deck's mana base.

https://magic.wizards.com/en/articles/archive/level-one/building-mana-base-2014-11-24

In general, the costs of entering the battlefield tapped go up as the format becomes faster or more powerful.