What is the prefered style for single decision and action statements?

if (var == true)
    doSomething();

if (var == 1)
    doSomething(1);
else if (var > 1 && var < 10)
    doSomething(2);
else
{
    validate(var);
    doSomething(var);
}

if ( a == b)    {
    doSomething();
}
else {
    doSomething();
}

if(a==b)
{
    doSomething();
}

if(a==b)
    doSomething();
    doSomethingElse();

if(a==b)
{
    doSomething();
    doSomethingElse();
}

if(something)
 DoOneThing();
else
  DoItDifferently();

if(something)
 DoOneThing();
else
  DoItDifferently();
  AlwaysGetsCalled();

if (cond1)
{
   SomeOperation();
   Another();
}
elseif (cond2)
{
   DoSomething();
}
else
{
   DoNothing();
   DoAnother();
}

if (cond1)
    DoFirst();
elseif (cond2)
    DoSecond();
else
    DoElse();

foreach (var s as Something)
    if (s == someCondition)
        yield return SomeMethod(s);

if (var == 1)
  doSomething();
doSomethingElse();

if (var == 1)
  doSomething();
  doSomethingExtra();
doSomethingElse();

If A == true
   FunctA();

If B == "Test"
{
   FunctB();
}

If A == false {
  //calls and whatnot
}
//or
If B == "BlaBla"
{
  //calls and whatnot
}
//or
If C == B
  {
  //calls and whatnot
  }

if (aString) free(aString);

do_something if (a == b)

if (a == b)
  do_something
  do_something_else
end

if (a == b)
    DoSomething();
    DoSomethingElse(); <-- outside if statement

if (a == b) DoSomething();

var c = (a == b) ? DoSomething() : DoSomethingElse();

var c = (a == b)
    ? AReallyReallyLongFunctionName()
    : AnotherReallyReallyLongFunctionOrStatement();

if (condition) {
    statements;
}

if (condition) {
    statements;
} else {
    statements;
}

if (condition) {
    statements;
} else if (condition) {
    statements;
} else {
    statements;
}

if (var == true)
{ doSomething(); }

if (cond)
   {
   //statement
   }

if (i != 0)
bar(i);
foo(i);

if(!ok)return;

do();

that();

thing();

do_something if condition;

do_something unless condition;

sub test{
  my($self,@args) = @_;

  return undef unless defined $self;

  # rest of code goes here

}