You're right. It is ''No siempre''

I'll add some examples to illustrate 'No siempre como manzanas rojas' (i dont always eat red apples) No siempre hago las cosas a tiempo (i don't always do things in time) Now... while writing the examples i noticed, if you're talking about past actions, like... 'i didn't always eat red apples', meaning there was a time in which you didn't eat them, it's better to use 'solía', 'i used to'. as in: 'Solía no comer manzanas rojas' (i used to not eat red apples) just a little bonus :P Take care