What works for me: I always consistently use "{%-" (the "remove all whitespace to the left" tag variant) for every command and comment. Every command starts on a new line. I only use the right-gobble in rare exceptional circumstances.
By sticking with this style I get consistent and predictable results.
If I need a new line, I'll do this:
Lorem ipsum.
{# blank line #}
{%- if condition %}
This could be indented.
{%- else %}{# condition #}
This might be indented.
{%- endif %}{# condition #}
Foo is indented.
Note that you need the minus on all commands, including the else clause, for consistent results.
Left gobble is preferred over right gobble because indentation is common, but trailing whitespace is rare.