Defining my role as a dominant

I've read a bit on the ending of the D/s (M/s) relationships.  There seems to be a variety of approaches (as one should expect), with what seems like two ends of a spectrum below.

• All one person in the relationship needs to do is text "STOP" to the other, and the relationship ends - no questions asked. 
• The relationship is not over until the D(M) says that the relationship can not be fixed.

I was also wondering if any D(M) has set up a severance package (not sure what it would be called in the BDSM world), as a last act of protection of the s?

I am open to comments from anyone who has seen it done well and from anyone who has seen it done poorly.