Implicit in a lot of the code I see seem to be some rules that I don't agree with.

One seems to be that there should be no more than one return statement. For example, something like

   Object result = null;

   ...

   if (result == null) {
       ...
   }

   if (result == null) {
       ...
   }

   if (result == null) {
       ...
   }

   if (result == null) {
       ...
   }

   ... and on and on ...

   return result;

More often, though, it tends goes like

    Object result = null;
    try {
        ...
        result = ...;
    } catch (Exception e) {
        ...
    }
    return result;

There also seems to be a rule that a result variable has to be declared, so I see things like

    Object result = ...;
    return result;

where I would just write

    return ...;

And then there's code from beginners that don't seem to realize that boolean expressions result in boolean values

    boolean result;
    if (...)
        result = true;
    else
        result = false;
    return result;