Although the example in the question are impersonal se and not reflexive se, they do follow many of the same rules. The meanings are completely different, but look at these examples:
Spanish is spoken. Se habla español.
Spanish speaks itself. Se habla español. (Español se habla.)
The word order could go either way.
Cars are sold. Se venden coches.
Cars sell themselves. Se venden coches.
While they have completely different meanings, if you're trying to formulate an impersonal construction, it can be helpful for the verb agreement and structure to think of it (loosely) as a reflexive sentence.
From textbook rules, the impersonal se uses the same placement as the reflexive se.
Se me rompió el brazo. My arm was broken.
Impersonal se followed by indirect object pronoun.
Once again, I find it helpful to form this sentence in my head as "The arm broke itself to me." It helps me to structure the sentence correctly even if this isn't actually reflexive.
An example of the same pronoun order with reflexive se:
Se los pone. He puts them on.
Reflexive se followed by direct object pronoun.
Now for what I've heard and read but not seen rules for:
No se puede tocarlos.
Impersonal se is split from the direct object los.
I've never seen this done with a reflexive se that I can recall.
Please correct anything that I've missed or misstated.