What are common pitfalls when using IF statements in PHP, as seen in the forum thread?

Common pitfalls when using IF statements in PHP include forgetting to use double equals `==` for comparison instead of a single equals `=` for assignment, not properly handling data types when comparing values, and not using logical operators like `&&` and `||` correctly.

// Incorrect comparison using single equals sign
$number = 5;
if($number = 5){
    echo "Number is 5";
}

// Correct comparison using double equals sign
$number = 5;
if($number == 5){
    echo "Number is 5";
}