Best practices

There are other things not covered by PEAR Coding Standards which are mostly subject of personal preference and not directly related to readability of the code. Things like "single quotes vs double quotes" are features of PHP itself to make programming easier and there are no reasons not use one way in preference to another. Such best practices are left solely on developer to decide. The only recommendation could be made to keep consistency within package and respect personal style of other developers.

Readability of code blocks

Related lines of code should be grouped into blocks, separated from each other to keep readability as high as possible. The definition of "related" depends on the code :)

For example:

<?php

if ($foo) {
    
$bar 1;
}
if (
$spam) {
    
$ham 1;
}
if (
$pinky) {
    
$brain 1;
}
?>

is a lot easier to read when separated:

<?php

if ($foo) {
    
$bar 1;
}

if (
$spam) {
    
$ham 1;
}

if (
$pinky) {
    
$brain 1;
}
?>

Return early

To keep readability in functions and methods, it is wise to return early if simple conditions apply that can be checked at the beginning of a method:

<?php

function foo($bar$baz)
{
    if (
$foo) {
        
//assume
        //that
        //here
        //is
        //the
        //whole
        //logic
        //of
        //this
        //method
        
return $calculated_value;
    } else {
        return 
null;
    }
}
?>

It's better to return early, keeping indentation and brain power needed to follow the code low.

<?php

function foo($bar$baz)
{
    if (!
$foo) {
        return 
null;
    }

    
//assume
    //that
    //here
    //is
    //the
    //whole
    //logic
    //of
    //this
    //method
    
return $calculated_value;
}
?>