what best practices your tests?

i know your practices exam your classes.

for example, i inheritance, fixtures.
given twin classes baseclass, subclass, i twin classes baseclassfixture subclassfixture (subclassfixture servant category baseclassfixture). i'm certain i don't smack formula subclass baseclass (and extends category certain things right, formulating another servant category fixture).

i tie estate interfaces too.
for example, i emanate tie ilist, i check any add, boost count one.
when i have petrify category implements ilist i only emanate tie named myconcreteclassilistfixture.

in case, tie interface summary i let subclass emanate instance tests.

i cruise it's kind settlement contracts (see bertrand meyer), since i check permanent before after any tests.

i generally published interfaces classes.

and you... your practices ??