Write a warrant that explains how a piece of evidence actually supports the claim, rather than leaving the connection unstated.
Evidence does not explain itself. A warrant is the sentence (or two) where you tell the reader exactly why this evidence supports your claim. Without a warrant, a reader has to guess your reasoning -- and readers should never have to guess.
A warrant usually sounds like "This shows that..." or "Because of this, ..." followed by the connection back to your claim. Skilled writers do not just drop a fact and move on; they explain what the fact proves.
Mastery looks like: They can write a warrant sentence that clearly explains why a specific piece of evidence supports the claim.
Common stumbles: Restating the evidence in different words instead of explaining why it matters; leaving the connection to the claim implied.