When using snippets in your projects a number of things should be considered
It is a good idea to put non default robot configuration that is needed to execute the steps inside the snippet on the steps of the snippet instead of having to remember to set them on each robot that uses the Snippet.
When inserting a snippet into a robot, take care that names of variables defined on the snippet do not conflict with variables defined on the robot. Design Studio can handle a situation where a variable defined on the snippet has the same name as a variable defined on the robot. Good practice is to primarily define variables on the snippet if they are needed for the snippet to work in another context. This makes reuse of the snippet easier.
It is good practice to document the context in terms of named tags and/or windows needed in order for the snippet to work in the description of a snippet.
A snippet may contain Snippet steps referencing other snippets. However, it is not legal to have cyclic references where a snippet ultimately contains itself. Design Studio will report an error in that case. So be careful when including snippets inside snippets.